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CHEMICAL  WARFARE 


Vl^  Qraw-JJillBock  (h  7ne 

PUBLISHERS     OF     BOOKS      F  O  Ps_y 

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rrMMMlffiffiiMI^^ 


CHEMICAL  WARFARE 


BY 


AMOS  A.  FRIES    ^"-^^"^^^ 


Brigadier-General,  C.  W.  S.,  U.  S.  A. 
Chief,  Chemical  Warfare  Service 


CLARENCE  J.  WEST 

Major,  C.  W.  S.  Reserve  Corps,  U.  S.  A. 
National  Research  Council 


First  Edition 


McGRAW-HILL   BOOK   COMPANY,  Inc. 

NEW  YORK:  370  SEVENTH  AVENUE 

LONDON:  6  &  8  BOUVERIE  ST..  E.  C.  4 

1921 


IJQ. 


Copyright,  1921,  by  the 
McGraw-Hill  Book  Company,  Inc. 


PREFACE 


Shortly  after  the  signing  of  the  Armistice,  it  was  realized  that 
the  story  of  Chemical  Warfare  should  be  written,  partly  because 
of  its  historical  value,  and  partly  because  of  the  future  needs  of 
a  textbook  covering  the  fundamental  facts  of  the  Service  for  the 
Army,  the  Reserve  Officer,  the  National  Guard,  and  even  the 
Civilian  Chemist.  The  present  work  was  undertaken  by  both 
authors  as  a  labor  of  patriotism  and  because  of  their  interest  in 
the  Service. 

The  two  years  which  have  elapsed  since  the  initial  discussion 
of  the  outlines  of  the  book  have  thoroughly  convinced  us  of  the 
need  of  such  a  work.  The  Engineers,  the  Medical  Department, 
and  most  of  the  other  branches  of  the  Army  have  their  recognized 
textbooks  and  manuals.  There  has  been  no  way,  however,  by 
which  the  uninformed  can  check  the  accuracy  of  statements 
regarding  Chemical  Warfare.  The  present  volume  will  serve,  in 
a  measure,  to  fill  this  gap.  That  it  does  not  do  so  more  completely 
is  due  in  part  to  the  fact  that  secrecy  must  still  be  maintained 
about  some  of  the  facts  and  some  of  the  new  discoveries  which  are 
the  property  of  the  Service.  Those  familiar  with  the  work  of  the 
Chemical  Warfare  Service  will  discover,  though,  that  the  follow- 
ing pages  contain  many  statements  which  were  zealously  guarded 
secrets  two  years  ago.  This  enlarged  program  of  publicity  on 
the  part  of  the  Chief  of  the  Service  is  being  justified  every  day 
by  the  ever-increasing  interest  in  this  branch  of  warfare.  Where 
five  men  were  discussing  Chemical  Warfare  two  years  ago,  fifty 
men  are  talking  about  the  work  and  the  possibilities  of  the 
Service  to-day.  It  is  hoped  that  the  facts  here  presented  may 
further  increase  the  interest  in  Chemical  Warfare,  for  there  is  no 
question  but  that  it  must  be  recognized  as  a  permanent  and  a 
very  vital  branch  of  the  Army  of  every  country.  Reasons  for 
this  will  be  found  scattered  through  the  pages  of  this  book. 

vii 


viii  PREFACE 

It  should  be  explained  that  this  is  in  no  sense  a  complete 
historical  sketch  of  the  development  and  personnel  of  the  Chem- 
ical Warfare  Service.  At  least  two  more  volumes  are  needed, — 
one  on  the  Manufacture  of  Poisonous  Gases  and  one  on  the 
Tactics  of  Chemical  Warfare.  We  have  purposely  refrained 
from  an  attempt  to  give  credit  to  individuals  for  the  accomplish- 
ments of  the  various  Divisions  of  the  Service,  because  such  an 
attempt  would  have  made  the  book  too  voluminous,  and  would 
have  defeated  the  primary  purpose,  namely,  that  it  should  pre- 
sent the  information  in  as  concise  manner  as  possible.  The 
published  and  unpublished  materials  of  the  files  of  all  the 
Divisions  have  been  freely  drawn  upon  in  writing  the  various 
chapters,  and  many  old  C.  W.  S.  men  will  undoubtedly  recog- 
nize whole  sentences  which  they  wrote  under  the  stress  of  the 
laboratory  or  plant  ''battle  front."  May  these  few  lines  be  an 
acknowledgment  of  their  contributions.  Those  who  desire  to 
consult  the  literature  of  Chemical  Warfare  will  find  a  fairly 
complete  bibliography  (to  about  the  middle  of  1919)  in  ''Special 
Libraries"  for  November,  1919. 

Special  acknowledgment  is  made  to  Dr.  G.  J.  Esselen,  Jr., 
for  having  read  the  manuscript  and  for  helpful  and  construc- 
tive criticisms.  Many  of  the  figures  are  reproduced  by  permis- 
sion of  the  Journal  of  Industrial  and  Engineering  Chemistry; 
those  showing  the  Nelson  cell  were  furnished  by  the  Samuel  M. 
Green  Company. 

Amos  A.  Fries, 
Aug.  1,  1921.  Clarence  J.  West. 


FOREWORD 


After  all  peaceful  means  of  settling  disputes  between  nations 
have  been  resorted  to  and  have  failed,  war  is  often  declared  J)y 
one  of  the  disputants  for  the  purpose  of  imposing  its  will  upon 
the  other  by  force.  In  order  to  accomplish  this,  a  superiority 
must  be  established  over  the  a'dversary  in  trained  men  and  in 
implements  of  war. 

Men  are  nothing  in  modern  war  unless  they  are  equipped  with 
the  most  effective  devices  for  killing  and  maiming  the  enemy's 
soldiers  and  thoroughly  trained  in  the  use  of  such  implements. 

History  proves  that  an  effective  implement  of  war  has  never 
been  discarded  until  it  becomes  obsolete. 

It  is  impossible  to  humanize  the  act  of  killing  and  maiming 
the  enemy's  soldiers,  and  there  is  no  logical  grounds  on  which 
to  condemn  an  appliance  so  long  as  its  application  can  be  so 
confined.  Experiments  in  this  and  other  countries  during  the 
World  War  completely  established  the  fact  that  gas  can  be  so 
confined.  The  range  of  gas  clouds  is  no  greater  than  that  of 
artillery  and  the  population  in  the  area  behind  the  front  line 
must,  if  they  remain  in  such  range,  take  their  chance.  The 
danger  area  in  the  future  will  be  known  to  all. 

As  the  first  Director  of  the  Chemical  Warfare  Service,  U.  S. 
Army,  I  speak  with  some  experience  when  I  say  that  there  is  no 
field  in  which  the  future  possibilities  are  greater  than  in  chemical 
warfare,  and  no  field  in  which  neglect  to  keep  abreast  of  the 
times  in  research  and  training  w^ould  be  more  disastrous. 

Notwithstanding  the  fact  that  gas  was  used  in  the  World 
War  two  years  before  the  United  States  entered  the  fray,  prac- 
tically nothing  was  done  in  this  country  before  April,  1917, 
towards  the  development  of  any  chemical  warfare  appliances, 
offensive  or  defensive,  and  had  it  not  been  for  the  ability  of  an 
ally  to  supply  our  troops  with  such  appliances,  they  would  have 


X  FOREWORD 

been  as  defenseless  as  the  Canadians  were  at  Ypres  when  the 
Germans  sent  over  their  first  gas  cloud. 

This  book  recites  the  troubles  and  successes  of  this  new 
service  under  the  stress  of  war  for  which  it  was  unprepared  and 
I  trust  that  its  perusal  will  create  a  public  opinion  that  will 
insist  upon  chemical  preparation  for  war. 

I  feel  that  this  book  will  show  that  the  genius  and  patriotism 
displayed  by  the  chemists  and  chemical  engineers  of  the  country 
were  not  surpassed  in  any  other  branch  of  war  work  and  that  to 
fail  to  utilize  in  peace  times  this  talent  would  be  a  crime. 

William  L.  Sibert, 

Major  General,  United  States  Army, 
Retired. 


CONTENTS 


PAGE 

Preface vii 

Foreword ix 

CHAPTER 

I.  The  History  of  Poison  Gases 1 

II.  Modern  Development  of  Gas  Warfare 10 

III.  Development  of  the  Chemical  Warfare  Service 31 

IV.  The  Chemical  Warfare  Service  in  France 72 

V.  Chlorine 116 

VI.  Phosgene 126 

VII.  Lachrymators 137 

VIII.  Chloropicrin 144 

IX.  Dichloroethylsulfide  (Mustard  Gas) 150 

X.  Arsenic  Derivatives 180 

^.  Carbon  Monoxide 190 

(Xll.  Development  of  the  Gas  Mask 195 

XIII.  Absorbents 237 

XIV.  Testing  Absorbents  and  Gas  Masks 259 

XV.  Other  Defensive  Measures 272 

XVI.  Screening  Smokes 285 

XVII.  Toxic  Smokes 313 

XVIII.  Smoke  Filters 322 

XIX.  Signal  Smokes 330 

XX.  Incendiary  Materials 336 

JQQ^The  Pharmacology  of  War  Gases 353 

/Hemical  Warfare  in  Relation  to  Strategy  and  Tactics  . . .  363 

[II. ^HE  Offensive  Use  of  Gas 385 

^ 'Defense  against  Gas 405 

^^^,^EACE  Time  Uses  of  Gas. 427 

!VI,--The  Future  of  Chemical  Warfare 435 

Index 440 


CHEMICAL   WARFARE 


CHAPTER    I 
THE  HISTORY  OF  POISON  GASES  ^ 

The  introduction  of  poison  gases  by  the  Germans  at  Ypres 
in  April,  1915,  marked  a  new  era  in  modern  warfare.  The 
popular  opinion  is  that  this  form  of  warfare  was  original  with 
the  Germans.  Such,  however,  is  not  the  case.  Quoting  from 
an  article  in  the  Candid  Quarterly  Review,  4,  561,  "All  they 
can  claim  is  the  inhuman  adoption  of  devices  invented  in  Eng- 
land, and  by  England  rejected  as  too  horrible  to  be  entertained 
even  for  use  against  an  enemy."  But  the  use  of  poison  gases 
is  e ven,^JL an=«arlier-t)rigin"ttign  4to_  ai'tiele-^alaiins. 

The  first  recorded  effort  to  overconie  an  enemy  by  the  genera- 
tion of  poisonous  and  suffocating  gases  seems  to  have  been  in 
the  wars  of  the  Athenians  and  Spartans  (431-404  B.C.)  when, 
besieging  the  cities  of  Platea  and  Bclium,  the  Spartans  saturated 
wood  with  pitch  and  sulfur  and  burned  it  under  the  waPs 
of  these  cities  in  the  hope  of  choking  the  defenders  and  rendering 
the  assault  less  difficult.  Similar  jiscs-_of-jKdsonous  gases  are 
recorded  during  the  Middle  AgesT  In  effect  they^wefe 
our  modernlTmk  baTTs,  but  were  projected  by  squirts  or  in 
bottles  after  the  manner  of  a  hand  grenade.  The  legend  is  told 
of  Prester  John  (about  the  eleventh  century),  that  he  stuffed 
copper  figures  with  explosives  and  combustible  materials  which, 
emitted  from  the  mouths  and  nostrils  of  the  effigies,  played  great 
havoc. 

The  idea  referred  to  by  the  writer  in  the  Candid  Quarterly 
Review,  is  from  the  pen  of  the  English  Lord  Dundonald,  which 
^Tbis  chapter  originally  appeared  in  Science,  Vol.  49,  pp.  412-417  (1919). 


2  CHEMICAL  WARFARE 

appe8He<J  ill  th^  publication  entitled  ''The  Panmure  Papers.'* 
This  is  an  extremely  dull  record  of  an  extremely  dull  person, 
only  rendered  interesting  by  the  one  portion,  concerned  with 
the  use  of  poison  gases,  which,  it  is  said,  ''should  never  have 
been  published  at  all/' 

That  portion  of  the  article  from  the  Candid  Quarterly  Review 
dealing  with  the  introduction  of  poisonous  gas  by  the  Germans, 
and  referred  to  in  the  first  paragraph  above,  is  quoted  in  full 
as  follows; 

"The  great  Admiral  Lord  Dundonald — perhaps  the  ablest  sea  cap- 
tain ever  known,  not  even  excluding  Lord  Nelson — was  also  a  man 
of  wide  observation,  and  no  mean  chemist.  He  had  been  struck  in 
1811  by  the  deadly  character  of  the  fumes  of  sulphur  in  Sicily;  an^d, 
when  the  Crimean  War  was  being  waged,  he  communicated  to  the 
English  government,  then  presided  over  by  Lord  Palmerston,  a  plan 
for  the  reduction  of  Sebastopol  by  sulphur  fumes.  The  plan  was 
imparted  to  Lord  Panmure  and  Lord  Palmerston,  and  the  way  in 
which  it  was  received  is  so  illustrative  of  the  trickery  and  treachery 
of  the  politician  that  it  is  worth  while  to  quote  Lord  Palmerston's 
private  communication  upon  it  to  Lord  Panmure: 

"Lord  Palmerston  to  Lord  Panmure 

"  'House  of  Commons,  7th  August,  1855 

"  *I  agree  with  you  that  if  Dundonald  will  go  out  himself  to  super- 
intend and  direct  the  execution  of  his  scheme,  we  ought  to  accept 
his  offer  and  try  his  plan.  If  it  succeeds,  it  will,  as  you  say,  save 
a  great  number  of  English  and  French  lives;  if  it  fails  in  his  hands, 
we  shall  be  exempt  from  blame,  and  if  we  come  in  for  a  small  share 
of  the  ridicule,  we  can  bear  it,  and  the  greater  part  will  fall  on  him. 
You  had  best,  therefore,  make  arrangement  with  him  without  delay, 
and  with  as  much  secrecy  as  the  nature  of  things  will  admit  of.' 

"Inasmuch  as  Lord  Dundonald's  plans  have  already  been  deliberately 
published  by  the  two  persons  above  named,  there  can  be  no  harm 
in  now  republishing  them.  They  will  be  found  in  the  first  volume 
of  'The  Panmure  Papers'   (pp.  340-342)   and  are  as  follows: 

"'(Enclosure) 
"  'Brief  Preliminary  Observations 
"  'It  was  observed  when  viewing  the  Sulphur  Kilns,  in  July,  1811, 
that  the  fumes  which  escaped  in  the  rude  process  of  extracting  the 


THE  HISTORY  OF  POISON  GASES  3 

material,  though  first  elevated  by  heat,  soon  fell  to  the  ground,  destroy- 
ing all  vegetation,  and  endangering  animal  life  to  a  great  distance, 
and  it  was  asserted  that  an  ordinance  existed  prohibiting  persons 
from  sleeping  within  the  distance  of  three  miles  during  the  melting 
season. 

"  'An  application  of  these  facts  was  immediately  made  to  Military 
and  Naval  purposes,  and  after  mature  consideration,  a  Memorial  was 
presented  on  the  subject  to  His  Royal  Highness  the  Prince  Regent 
on  the  12th  of  April,  1812,  who  was .  graciously  pleased  to  lay  it  before 
a  Commission,  consisting  of  Lord  Keith,  Lord  Exmouth  and  General 
and  Colonel  Congreve  (afterwards  Sir  William),  by  whom  a  favorable 
report  having  been  given.  His  Royal  Highness  was  pleased  to  order 
that  secrecy  should  be  maintained  by  all  parties. 

"'(Signed)  Dundonald 
*  "  7th  August,  1855' 

"  'Memorandum 

"  'Materials  required  for  the  expulsion  of  the  Russians  from  Sebas- 
topol:  Experimental  trials  have  shown  that  about  five  parts  of  coke 
effectually  vaporize  one  part  of  sulphur.  Mixtures  for  land  service, 
where  weight  is  of  importance,  may,  however,  probably  be  suggested 
by  Professor  Faraday,  as  to  operations  on  shore  I  have  paid  little 
attention.  Four  or  five  hundred  tons  of  sulphur  and  two  thousand  tons 
of  coke  would  be  suffjcient. 

"  'Besides  these  materials,  it  would  be  necessary  to  have,  say,  as 
much  bituminous  coal,  and  a  couple  of  thousand  barrels  of  gas  or 
other  tar,  for  the  purpose  of  masking  fortifications  to  be  attacked, 
or  others  that  flank  the  assailing  positions. 

"  'A  quantity  of  dry  firewood,  chips,  shavings,  straw,  hay  or  other 
such  combustible  materials,  would  also  be  requisite  quickly  to  kindle 
the  fires,  which  ought  to  be  kept  in  readiness  for  the  first  favourable 
and  steady  breeze. 

"  'Dundonald 

"  '7th  August,  1855' 

"'Note. — The  objects  to  be  accomplished  being  specially  stated  the 
responsibility  of  their  accomplishment  ought  to  rest  on  those  who 
direct  their  execution. 

"  'Suppose  that  the  Malakoff  and  Redan  are  the  objects  to  be 
assailed  it  might  be  judicious  merely  to  obscure  the  Redan  (by  the 
smoke  of  coal  and  tar  kindled  in  'The  Quarries'),  so  that  it  could  not 
annoy  the  Mamelon,  where  the  sulphur  fire  would  be  placed  to  expel 


4  CHEMICAL  WARFARE 

the  garrison  from  the  Malakoff,  which  ought  to  have  all  the  cannon 
that  can  be  turned  towards  its  ramparts  employed  in  overthrowing 
its  undefended  ramparts. 

"  'There  is  no  doubt  but  that  the  fumes  will  envelop  all  the  defenses 
from  the  Malakoff  to  the  Barracks,  and  even  to  the  line  of  battleship, 
the  Twelve  Apostles,  at  anchor  in  the  harbour. 

"  'The  two  outer  batteries,  on  each  side  of  the  Port,  ought  to  be 
smoked,  sulphured,  and  blown  down  by  explosion  vessels,  and  their 
destruction  completed  by  a  few  ships  of  war  anchored  under  cover 
of  the  smoke.' 

"That  was  Lord  Dundonald's  plan  in  1855,  improperly  published 
in  1908,  and  by  the  Germans,  who  thus  learnt  it,  ruthlessly  put  into 
practise  in  1915. 

"Lord  Dundonald's  memoranda,  together  with  further  elucidatory 
notes,  were  submitted  by  the  English  government  of  that  day  to  a 
committee  and  subsequently  to  another  committee  in  which  Lord  Play- 
fair  took  leading  part.  These  committees,  with  Lord  Dundonald's  plans 
fully  and  in  detail  before  them,  both  reported  that  the  plans  were 
perfectly  feasible;  that  the  effects  expected  from  them  would  un- 
doubtedly be  produced ;  but  that  those  effects  were  so  horrible  that  no 
'l  honorable  combatant  could  use  the  means  required  to  produce  them. 
The  committee  therefore  recommended  that  the  scheme  should  not  be 
adopted;  that  Lord  Dundonald's  account  of  it  should  be  destroyed. 
How  the  records  were  obtained  and  preserved  by  those  who  so  im- 
properly published  them  in  1908  we  do  not  know.  Presumably  they 
were  found  among  Lord  Panmure's  papers.  Admiral  Lord  Dundonald 
himself  was  certainly  no  party  to    their  publication." 

One  of  the  early,  if  not  the  earliest  suggestion  as  to  the  use 
of  poison  gas  in  shell  is  found  in  an  article  on  ** Greek  Fire,** 
by  B.  W.  Richardson.^ 

He  says: 

"I  feel  it  a  duty  to  state  openly  and  boldly,  that  if  science  were 
to  be  allowed  her  full  swing,  if  society  would  really  allow  that  'all 
is  fair  in  war,'  war  might  be  banished  at  once  from  the  earth  as  a 
game  which  neither  subject  nor  king  dare  play  at.  Globes  that  could 
distribute  liquid  fire  could  distribute  also  lethal  agents,  within  the 
breath  of  which  no  man,  however  puissant,  could  stand  and  live.  From 
the    summit    of   Primrose   Hill,    a    few    hundred    engineers,   properly 

^Popular  Science  Review,  3,  176  (1864). 


THE  HISTORY  OF  POISON  GASES  5 

prepared,  could  render  Regent's  Park,  in  an  incredibly  short  space 
of  time,  utterly  uninhabitable;  or  could  make  an  army  of  men,  that 
should  even  fill  that  space,  fall  with  their  arms  in  their  hands,  prostrate 
and  helpless  as  the  host  of  Sennacherib. 

"The  question  is,  shall  tliese  things  be?  1  do  not  see  that  humanity 
should  revolt,  for  would  it  not  be  better  to  destroy  a  host  in  Regent's 
Park  by  making  the  men  fall  as.  in  a  mysticaL-skep^  than  to  let  down 
on  them  another  host  to  break  their  ban^  tea^  tli^ir  limbs  asunder 
and  gouge  out  their  entrails  with  three-cornered^  pikes ;  leaving  a  vast 
majority  undead,  and  writhing  for  hours  in  torments  of  the  damned? 
I  conceive,  for  one,  that  science  would  be  blessed  in  spreading  her 
wings  on  the  blast,  and  breathing  into  the  face  of  a  desperate  horde 
of  men  prolonged  sleep — for  it  need  not  necessarily  be  a  death —  : 
which  they  could  not  grapple  with,  and  which  would  yield  them  up 
with  their  implements  of  murder  to  an  enemy  that  in  the  immensity 
of  its  power  could  afford  to  be  merciful  as  Heaven. 

"The  question  is,  shall  these  things  be?  I  think  they  must  be.  By 
what  compact  can  they  be  stopped?  It  were  improbable  that  any 
congress  of  nations  could  agree  on  any  code  regulating  means  of 
destruction;  but  if  it  did,  it  were  useless;  for  science  becomes  more 
powerful  as  she  concentrates  her  forces  in  the  hands  of  units,  so 
that  a  nation  could  only  act,  by  the  absolute  and  individual  assent 
of  each  of  her  representatives.  Assume,  then,  that  France  shall  lay 
war  to  England,  and  by  superior  force  of  men  should  place  immense 
hosts,  well  armed,  on  English  soil.  Is  it  probable  that  the  units 
would  rest  in  peace  and  allow  sheer  brute  force  to  win  its  way  to 
empire?  Or  put  English  troops  on  French  soil,  and  reverse  the 
question  ? 

"To  conclude.  War  has,  at  this^  moment,  reached,  in  its  details, 
such  an  extravagance  of  horror  and  cruelty,  that  it  can  not  be^  made 
worse  by  any  art,  and  can  only  be  made  more  merciful  by  being  ; 
rendered  more  terribly  energetic.  Who  that  had  to  die  from  a  blow 
would  not  rather  place  his  head  under  Nasmyth's  hammer,  than  submit 
it  to  a  drummer-boy  armed  with  a  ferrule?" 

The  Army  and  Navy  Register  of  May  29,  1915,  reports  that 

"among  the  recommendations  forwarded  to  the  Board  of  Ordnance 
and  Fortifications  there  may  be  found  many  suggestions  in  favor  of 
the  asphyxiation  process,  mostly  by  the  employment  of  gases  contained 
in  bombs  to  be  thrown  within  the  lines  of  the  foe,  with  varying  effects 
from  peaceful  slumber  to  instant  death.     One  ingenious  person  sug-  | 


6  CHEMICAL  WARFARE 

gested  a  bomb  laden  to  its  full  capacity  with  snuff,  which  should 
be  so  evenly  and  thoroughly  distributed  that  the  enemy  would  be 
convulsed  with  sneezing,  and  iu  this  period  of  paroxysm  it  would 
be  possible  to  creep  up  on  him  and  capture  him  in  the  throes  of  the 
convulsion." 

That  the  probable  use  of  poisonous  gas  has  often  been  in 
the  minds  of  military  men  during  recent  times  is  evidenced  by 
the  fact  that  at  the  Hague  Conference  in  1899  several  of  the 
more  prominent  nations  of  Europe  and  Asia  pledged  them- 
selves not  to  use  projectiles  whose  only  object  was  to  give  out 
suffocating  or  poisonous  gases.  Many  of  the  Powers  did  not 
sign  this  declaration  until  later.  Germany  signed  and  ratified 
it  on  Sept.  4,  1900,  but  the  United  States  never  signed  it. 
Further,  this  declaration  was  not  to  be  binding  in  case  of  a  war 
in  which  a  non-signatory  was  or  became  a  belligerent.  Admiral 
Mahan,  a  United  States  delegate,  stated  his  position  in  regard 
to  the  use  of  gas  in  shell  (at  that  time  an  untried  theory)  as 
follows : 

\,  "The  reproach  of  cruelty  and  perfidy  addressed  against  these  sup- 

posed shells  was  equally  uttered  previously  against  fire-arms  and  tor- 
I  pedoes,  although  both  are  now  employed  without  scruple.  It  is  illogical 
i  and  not  demonstrably  humane  to  be  tender  about  asphyxiating  men 
with  gas,  when  all  are  prepared  to  admit  that  it  is  allowable  to  blow 
the  bottom  out  of  an  ironclad  at  midnight,  throwing  four  or  five 
hundred  men  into  the  sea  to  be  choked  by  the  water,  with  scarcely 
the  remotest  chance  to  escape." 

At  the  Hague  Congress  of  1907,  article  23  of  the  rules 
adopted  for  war  on  land  states: 

"It   is   expressly   forbidden    (a),  to  employ   poisons   or   poisonous 


Before  the  War  suffocating  cartridges  were  shot  from  the 
cartridge-throwing  rifle  of  26  mm!  These  cartridges  were 
charged  with  ethyl  bromoacetate,  a  slightly  suffocating  and 
non-toxic  lachrymator.  They  were  intended  for  attack  on  the 
flanking  works  of  permanent  fortifications,  flanking  casements 
or  caponiers,  into  which  the  enemy  tried  to  make  the  cartridges 


THE  HISTORY  OF  POISON  GASES  7 

penetrate  through  the  narrow  slits  used  for  loopholes.  The  men 
who  were  serving  the  machine  guns  or  the  cannon  of  the  flanking 
Avorks  would  have  been  bothered  by  the  vapor  from  the  ethyl 
bromoacetate,  and  the  assailant  would  have  profited  by  their 
disturbance  to  get  past  the  obstacle  presented  by  the  fortifica- 
tion. The  employment  of  these  devices,  not  entailing  death,  did 
not  contravene  the  Hague  conventions. 

The  only  memorable  operations  in  the  course  of  which  these 
devices  were  used  before  the  War  was  the  attack  on  the  Bonnet 
gang  at  Choisy-le-roi. 

In  connection  with  the  suggested  use  of  sulfur  dioxide 
by  Lord  Dundonald  and  the  proposed  use  of  poisonous  gases 
in  shell,  the  following  description  of  a  charcoal  respirator  by 
Dr.  J.  Stenhouse,^  communicated  by  Dr.  George  Wilson  in  1854, 
is  of  interest. 

"Dr.  Wilson  commenced  by  stating  that,  having  read  with  much 
interest  the  account  of  Dr.  Stenhouse's  researches  on  the  deodorizing 
and  disinfecting  properties  of  charcoal,  and  the  application  of  these 
to  the  construction  of  a  new  and  important  kind  of  respirator,  he 
had  requested  the  accomplished  chemist  to  send  one  of  his  instruments 
for  exhibition  to  the  society,  which  he  had  kindly  done.  Two  of  the 
instruments  were  now  on  the  table,  differing,  however,  so  slightly  in 
construction,  that  it  would  be  sufficient  to  explain  the  arrangement 
of  one  of  them.  Externally,  it  had  the  appearance  of  a  small  fencing- 
niask  of  wire  gauze,  covering  the  face  from  the  chin  upwards  to  the 
bridge  of  the  nose,  but  leaving  the  eyes  and  forehead  free.  It  consisted, 
essentially,  of  two  plates^  of  wire  gauze,  separated  from  each  other 
by  a  space  of  about  one-fourth  or  one-eighth  of  an  inch,  so  as  to 
form  a  small  cage  filled  with  small  fragments  of  charcoal.  The  frame 
of  the  cage  was  of  copper,  but  the  edges  were  made  of  soft  lead, 
and  were  lined  with  velvet,  so  as  to  admit  of  their  being  made  to  fit 
the  cheeks  tightly  and  inclose  the  mouth  and  nostrils.  By  this  arrange- 
ment, no  air  could  enter  the  lungs  without  passing  through  the  wire 
gauze  and  traversing  the  charcoal.  An  aperture  is  provided  with  a 
screw  or  sliding  valve  for  the  removal  and  replenishment  of  the 
contents  of  the  cage,  which  consist  of  the  siftings  or  riddlings  of  the 
lighter  kinds  of  wood  charcoal.  The  apparatus  is  attached  to  the 
face  by  an  elastic  band  passing  over  the  crown  of  the  head  and  strings 
tying  behind,  as  in  the  case  of  the  ordinary  respirator.  The  important 
^  Trans.  Boyal  Scottish  Soc.  Arts,  4,  Appendix  O,  198  (1854). 


8  CHEMICAL  WARFARE 

agent  in  this  instrument  is  the  charcoal,  which  has  so  remarkable  a 
power  of  absorbing  and  destroying  irritating  and  otherwise  irrespirable 
and  poisonous  gases  or  vapors  that,  armed  with  the  respirator,  spirits 
of  hartshorn,  sulphuretted  hydrogen,  hydrosulphuret  of  ammonia  and 
chlorine  may  be  breathed  through  it  with  impunity,  though  but  slightly 
diluted  with  air.  This  result,  first  obtained  by  Dr.  Stenhouse,  has 
been  verified  by  those  who  have  repeated  the  trial,  among  others  by 
Dr.  Wilson,  who  has  tried  the  vapors  named  above  on  himself  and 
four  of  his  pupils,  who  have  breathed  them  with  impunity.  The 
explanation  of  this  remarkable  property  of  charcoal  is  two-fold.  It 
has  long  been  known  to  possess  the  power  of  condensing  into  its  pores 
gases  and  vapors,  so  that  if  freshly  prepared  and  exposed  to  these, 
it  absorbs  and  retains  them.  But  it  has  scarcely  been  suspected  till 
recently,  when  Dr.  Stenhouse  pointed  out  the  fact,  that  if  charcoal 
be  allowed  to  absorb  simultaneously  such  gases  as  sulphuretted  hydrogen 
and  air,  the  oxygen  of  this  absorbed  and  condensed  air  rapidly  oxidizes 
and  destroys  the  accompanying  gas.  So  marked  is  this  action,  that 
if  dead  animals  be  imbedded  in  a  layer  of  charcoal  a  few  inches 
deep,  instead  of  being  prevented  from  decaying  as  it  has  hitherto  been 
supposed  that  they  would  be  by  the  supposed  antiseptic  powers  of 
the  charcoal,  they  are  found  by  Dr.  Stenhouse  to  decay  much  faster, 
whilst  at  the  same  time,  no  offensive  effluvia  are  evolved.  The  deo- 
dorizing powers  of  charcoal  are  thus  established  in  a  way  they  never 
have  been  before ;  but  at  the  same  time  it  is  shown  that  the  addition 
of  charcoal  to  sewage  refuse  lessens  its  agricultural  value  contem- 
poraneously with  the  lessening  of  odor.  From  these  observations,  which 
have  been  fully  verified,  it  appears  that  by  strewing  charcoal  coarsely 
powdered  to  the  extent  of  a  few  inches,  over  church-yards,  or  by 
placing  it  inside  the  coffins  of  the  dead,  the  escape  of  noisome  and 
poisonous  exhalations  may  be  totally  prevented.  The  charcoal  respirator 
embodies  this  important  discovery.  It  is  certain  that  many  of  the 
miasma,  malaria  and  infectious  matters  which  propagate  disease  in 
the  human  subjects,  enter  the  body  by  the  lungs,  and  impregnating 
the  blood  there,  are  carried  with  it  throughout  the  entire  body,  which 
they  thus  poison.  These  miasma  are  either  gases  and  vapors  or  bodies 
which,  like  fine  light  dust,  are  readily  carried  through  the  air;  more- 
over, they  are  readily  destroyed  by  oxidizing  agents,  which  convert 
them  into  harmless,  or  at  least  non-poisonous  substances,  such  as  water, 
carbonic  acid  and  nitrogen.  There  is  every  reason,  therefore,  for 
believing  that  charcoal  will  oxidize  and  destroy  such  miasma  as  effec- 
tually as  it  does  sulphuretted  hydrogen  or  hydrosulphuret  of  ammonia, 
and  thus  prevent  their  reaching  and  poisoning  the  blood.    The  intention 


THE  HISTORY  OF  POISON  GASES  9 

accordingly  is  that  those  who  are  exposed  to  noxious  vapors,  or  com- 
pelled to  breathe  infected  atmospheres,  shall  wear  the  charcoal 
respirator,  with  a  view  to  arrest  and  destroy  the  volatile  poisons 
contained  in  these.  Some  of  the  non-obvious  applications  of  the 
respirator  were  then  referred  to : 

"1.  Certain  of  the  large  chemical  manufacturers  in  London  are 
now  supplying  their  workmen  with  the  charcoal  respirators  as  a 
protection  against  the  more  irritating  vapors  to  which  they  are  exposed. 

"2.  Many  deaths  have  occurred  among  those  employed  to  explore 
the  large  drains  and  sewers  of  London  from  exposure  to  sulphuretted 
hydrogen,  etc.  It  may  be  asserted  with  confidence  that  fatal  results 
from  exposure  to  the  drainage  gases  will  cease  as  soon  as  the  respirator 
is  brought  into  use. 

"3.  In  districts  such  as  the  Campagna  of  Rome,  where  malaria 
prevails  and  to  travel  during  night  or  to  sleep  in  which  is  certainly 
followed  by  an  attack  of  dangerous  and  often  fatal  ague,  the  wearing 
of  the  respirator  even  for  a  few  hours  may  be  expected  to  render  the 
marsh  poison  harmless. 

"4.  Those,  who  as  clergymen,  physicians  or  legal  advisers,  have 
to  attend  the  sick-beds  of  sufferers  from  infectious  disorders,  may, 
on  occasion,  avail  themselves  of  the  protection  afforded  by  Dr.  Sten- 
house's  instrument  during  their  intercourse  with  the  sick. 

"5.  The  longing  for  a  short  and  decisive  war  has  led  to  the  inven- 
tion of  'a,  suffocating  bombshell,'  which  on  bursting,  spreads  far  and 
wide  an  irrespirable  or  poisonous  vapor;  one  of  the  liquids  proposed 
for  the  shell  is  the  strongest  ammonia,  and  against  this  it  is  believed 
that  the  charcoal  respirator  may  defend  our  soldiers.  As  likely  to 
serve  this  end,  it  is  at  present  before  the  Board  of  Ordnance. 

"Dr.  Wilson  stated,  in  conclusion,  that  Dr.  Stenhouse  had  no 
interest  but  a  scientific  one  in  the  success  of  the  respirators.  He  had 
declined  to  patent  them,  and  desired  only  to  apply  his  remarkable 
discoveries  to  the  abatement  of  disease  and  death.  Charcoal  had  long 
been  used  in  filters  to  render  poisonous  water  wholesome;  it  was  now 
to  be  employed  to  filter  poisonous  air." 


CHAPTER   II 

MODERN   DEVELOPMENT    OF    GAS    WARFARE 

The  use  of  toxic  gas  in  the  World  War  dates  from  April 
22,  1915,  ^hen  the  Germans  launched  the  first  cylinder  attack, 
employing  chlorine,  a  common  and  well-known  gas.  Judging 
from  the  later  experience  of  the  Allies  in  perfecting  this  form 
of  attack,  it  is  probable  that  plans  for  this  attack  had  been 
under  way  for  months  before  it  was  launched.  The  suggestion 
that  poisonous  gases  be  used  in  warfare  has  been  laid  upon 
Prof.  Nernst  of  the  University  of  Berlin  (Auld,  ^'Gas  and 
Flame,"  page  15),  while  the  actual  field  operations  were  said 
to  have  been  under  the  direction  of  Prof.  Haber  of  the  Kaiser 
Wilhelm  Physical  Chemical  Institute  of  Berlin.  Some  writers 
have  felt  that  the  question  of  preparation  had  been  a  matter 
of  years  rather  than  of  months,  and  refer  to  the  work  on 
industrial  gases  as  a  proof  of  their  statement.  The  fact  that 
the  gas  attack  was  not  more  successful,  that  the  results  to  be 
obtained  were  not  more  appreciated,  and  that  better  prepara- 
tion against  retaliation  had  not  been  made,  argues  against  this 
idea  of  a  long  period  of  preparation,  except  possibly  in  a  very 
desultory  way.  That  such  was  the  case  is  most  fortunate 
for  the  allied  cause,  for  had  the  German  high  command  known 
the  real  situation  at  the  close  of  the  first  gas  attack,  or  had 
that  attack  been  more  severe,  the  outcome  of  the  war  of  1914 
would  have  been  very  different,  and  the  end  very  much  earlier. 

First  Gas  Attack 

The  first  suggestion  of  a  gas  attack  came  to  the  British 
Army  through  the  story  of  a  German  deserter.  He  stated 
that  the  German  Army  w^as  planning  to  poison  their  enemy 
with  a  cloud  of  gas,  and  that  the  cylinders  had  already  been 

10 


MODERN  DEVELOPMENT  OF  GAS  WARFARE  11 

installed  in  the  trenches.  No  one  listened^to^  the  story,  because, 
first  of  all,  the  whole  procedure  seemed  so  impossible  and  also 
because,  in  spite  of  the  numerous  examples  of  German  bar-  / 
barity^  Jhe  JEnglish  did  not  believe  the  Germans  capable  of 
such  a  violation  of  the  Hague  rules  of  warfare.  The  story  ( 
appeared  in  the  summary  of  information  from  headquarters 
(''Comic  Cuts")  and  as  Auld  says  ''was  passed  for  informa- 
tion for  what  it  is  worth."  But  the  story  was  true,  and  on 
the  afternoon  of  the  22nd  of  April,  all  the  conditions  being 
ideal,  the  beginning  of  "gas  warfare"  was  launched.  Details 
of  that  first  gas  attack  will  always  be  meager,  for  the  simple 
reason  that  the  men  who  could  have  told  about  it  all  lie  in 
Flanders  field  where  the  poppies  grow. 

The  place  selected  was  in  the  northeast  part  of  the  Ypres 
salient,  at  that  part  of  the  line  where  the  French  and  British 
lines  met,  running  southward  from  where  the  trenches  left 
the  canal  near  Boesinghe.  The  French  right  was  held  by  the 
Regiment  of  Turcos,  while  on  the  British  left  were  the        / 

Canadians.    Auld  describes  the  attack  as  follows:  i^^l 

= —  ^^^K^. 

"Try   to   imagine   the   feelings   and   the   condition   of  the   colored 

troops  as  they  saw  the  vast  cloud  of  greenish-yellow  gas  spring  out 

of  the  gi'ound  and  slowly  move  down  wind  towards  them,  the  vapor 

cHnging  to  the  earth,  seeking  out  every  hole  and  hollow  and  filling 

the  trenches  and  shell  holes  as  it  came.    First  wonder,  then  fear;  then, 

as  the  first  fringes  of  the  cloud  enveloped  them  and  left  them  choking 

and  agonized  in  the  fight  for  breath — panic.     Those  who  could  move 

broke  and  ran,  trying,  generally  in  vain,  to  outstrip  the  cloud  which 

followed  inexorably  after  them."  " 

IMs  j)nlyjto_be  expected  that  the  first  feeling-conneeted 
with  gas  warfare  wag. jine_ol  harror.  That  side  of  it  is  very 
thrillingly  described  by  Rev.  0.  S.  Watkins  in  the  MetJwdist 
Recorder  (London).  After  describing  the  bombardment  of 
tlie  City  of  Ypres  from  April  20th  to  22nd  he  relates  that  in 
the  midst  of  the  uproar  came  the  poison  gas! 

"Going  into  the  open  air  for  a  few  moments'  relief  from  the 
stifling  atmosphere  of  the  wards,  our  attention  was  attracted  hy  very 
heavy  firing  to  the  north,  where  the  line  was  held  by  the  French. 
Evidently  a  Jiot  fight — and  eagerly  we  scanned  the  country  with  our 


12 


CHEMICAL  WARFARE 


<"•    flj  I 


MODERN  DEVELOPMENT  OF  GAS  WARFARE  13 

field  glasses  hoiking  to  glean  some  knowledge  of  the  progress  of  the 
battle.  Then  we  saw  that  which  ahuost  caused  our_  hearts  to,  stop 
beating — figures  running  wildly  and  in  confusion  over  the  fields. 

"  'The  French  have,  broken/  we  exclaimed.  We  hardly  believed 
our  words.  .  .  .  The  story  they  told  we  could  not  believe;  we  put 
it  down  to  their  terror-stricken  imaginings — a  greenish-gray  cloud  had 
swept  down  upon  them,  turning  yellow  as  it  traveled  over  the  country, 
blasting  everything  it  touched,  shriveling  up  the  vegetation.  5iQ_iuman  -^ 
courage  could  face  such  a  peril. 

"Then  there  staggered  into  our  midst  French  soldiers,  blinded, 
coughing,  chests  heaving,  faces  an  ugly  purple  color — lips  speechless 
with  agony,  and  behind  them,  in  the  gas-choked  trenches,  we  learned 
that  they  had  left  hundreds  of  dead  and  dying  coparades.  The  impossible 
was  only  too  true. 


^It  was  the  most  fiendish,  wicked  thing  I  have  ever  seen.' 


J 


^  It  must_be  said  here,  however,  that  this  was  true  only 
nccause  the  French  had  no  protection  against  the  gas.  Indeed, 
it  is  far  from  being  the  most  horrible  form  of  warfare,  provided 
both  sides  are  prepared  defensively  and  offensively.  Medical 
records  show  that_out  of  every,  JOO  Aniericans  gassed  less  than 
two  died,  and  as  far  as  records  of  four  years  show,  very  few 
are  permanently  injured.  Out  of  every  100  American  casualties 
from  all  forms  of  warfare  other  than  gas  more  than  25 
per  cent  died,  whilp  from  2  to  5  por  ^^^it  morp  arp  maini(.^rl, 
blinded  or  disfigured  for  life.  Various  forms  of  gas,  as  will 
be  shown  in  the  following  pages,  make  life  miserable  or  vision 
impossible  to  those  without  a  mask.    Yet  they  do  not  kill. 

Thus  instead  of  gas  warfare  being  the  most  horrible,Jt  is 
the  most  humane  where  both  sides  are  prepared  for  it,  while 
against  savage  or  unprepared  peoples  it  can  be  made  so  humane 
that  but  very  few  casualties  will  result. ,  __ 

The  development  of  methods  of  defense  against  gas  will 
be  discussed  in  a  later  chapter.  It  will  suffice  to  ^ay  here 
that,  in  response  to  an  appeal  from  Lord  Kitchener,  a  temporary 
protection  was  quickly  furnished  the  men.  This  was  known 
as  the  ** Black  Veiling"  respirator,  and  consisted  of  a  cotton 
pad  soaked  in  ordinary  washing  soda  solution,  and  later,  in 
a  mixture  of  washing  soda  and  '*hypo,"  to  which  was  added 
a  little  glycerine.    These  furnished  a  fair  degree  of  protection 


14  CHEMICAL  WARFARE 

to  the  men  against  chlorine,  the  only  gas  used  in  the  early 
attacks. 

Phosgene  Introduced 

The  use  of  chlorine  alone  continued  until  the  introduction  on 

December  19,  1915,  of  a  mixture  of  phosgene  with  the  chlorine. 

This  mixture  offered  many  advantages  over  the  use  of  chlorine 

alone  (see  Chapter  VI). 

The  Allies  were  able,  through  warning  of  the  impending 

use  of  phosgene,  to  furnish  a  means  of  protection  against  it. 
,  It  was  at  this  time  that  the  p  and  the  ph  helmets  were  devised, 

the  cotton  filling  being  impregnated  with  sodium  phenolate 
'  and  later  with  a  mixture  of  sodium  phenolate  and  hexameth- 

jylenetetramine.    This  helmet  was  used  until  the  Standard  Box 
(Kespirator  was  developed  by  the  late  Lt.  Col.  Harrison. 

Allies  Adopt  Gas 

For  a  week  or  two  the  Allies  were  very  hesitant  about  adopt- 
ing gas  warfare.  However,  when  the  repeated  use  of  gas  by  the 
Germans  made  it  evident  that,  in  spite  of  what  the  Hague  had 
to  say  about  the  matter,  gas  was  to  be  a  part,  and  as  later 
developments  showed,  a  very  important  part  of  modern  war- 
fare, they  realized  there  was  no  choice  on  their  part  and 
that  they  had  to  retaliate  in  like  manner.  This^  jLecision  was 
reached  in  May  of  1915.  It  was  followed  by  the  organization 
of  a  Gas  Service  and  intensive  work  on  the  part  of  chemists, 
^:«4^neers  and  physiologists.  It  was  September  25,  1915,  how- 
eveV,  before  the  English  were  in  a  position  to  render  a  gas 
attacK.  From  then  on  the  Service  grew  in  numbers  and  in 
impori^ance,  whether  viewed  from  the  standpoint  of  research, 
produc'L^ion,  or  field  operations. 

The  iVllies  of  course  adopted  not  only  chlorine  but  phosgene 
as  well,  si  Qce  both  were  cheap,  easy  of  preparation  and  effective. 
They  felt  during  the  early  part  of  the  War  that  they  should 
adopt  a  fjubstance  that  would  kill  instantly,  and  not  one  that 
would  cause  men  to  suffer  either  during  the  attack  or  through 
symptoms  which  would  develop  later  in  a  hospital.  For  this 
reason  a  large  amount  of  experimental  Avork  was  carried  out 


MODERN  DEVELOPMENT  OF  GAS  WARFARE  15 

on  hydrocyanic  acid,  particularly  by  the  French.  Since  this 
gas  has  a  very  low  density,  it  was  necessary  to  mix  with  it 
substances  which  would  tend  to  keep  it  close  to  the  ground 
during  the  attack.  Various  mixtures,  all  called  * '  vincennite, " 
were  prepared, — chloroform,  arsenic  trichloride  and  stannic 
chloride  being  used  in  varying  proportions  with  the  acid.  It 
was  some  time  before  it  was  definitely  learned  that  these  mix- 
tures were  far  from  being  successful,  both  from  the  standpoint 
of  stability  and  of  poisonous  properties.  While  the  French 
actually  used  these  mixtures  in  constantly  decreasing  quantities 
on  the  field  for  a  long  time,  they  were  ultimately  abandoned, 
though  not  until  American  chemists  had  also  carried  out  a 
large  number  of  tests.  However,  following  the  recommenda- 
tion of  the  American  Gas  Service  in  France  in  December,  1917, 
no  vincennite  was  ever  manufactured  by  the  United  States. 


Lachrymators 

Almost  simultaneously  with  the  introduction  of  the  gas 
wave  attacks,  in  which  liquefied  gas  under  pressure  was 
liberated  from  cylinders,  came  the  use  of  lachrymatory  or/tear 
gases./  These,  while  not  very  poisonous  in  the  concentrations^ 
used,  were  very  effective  in  incapacitating  men  through  the 
effects  produced  upon  their  eyes.  The  low  concentration 
required  (one  part  in  ten  million  of  sonie  lachrymators  is 
sufficient  to  make  vision  impossible  without  a  mask)  makes 
this  form  of  gas  warfare  very  economical  as  well  as  very 
effective.  Even  if  a  mask  does  completely  protect  against 
such  compounds,  their  use  compels  an  army  to  w^ar-lhe  mask 
indefinitely,  with  an  expenditure  of  shell  far  short  of  that 
required  ifjthe  much  more  deadly  gases  were  used.  Thus  Fries 
estimates  that  one  good  lachrymatory  shell  will  force  wearing 
the  mask  over  an  area  that  would  require  500  to  1000  phosgene 
shell  of  equal  size  to  produce  the  same  effect.  While  the 
number  of  actual  casualties  will  be  very  much  lower,  the  total 
effect  considered  from  the  standpoint  of  the  expenditure  of 
ammunition  and  of  the  objectives  gained,  will  be  just  as  valu- 
able.   So  great  is  the  harassing  value  of  tear  and  irritant  gases 


16  CHEMICAL  WARFARE 

that  the  next  war  will  see  them  used  in  quantities  approxi- 
mating that  of  the  more  poisonous  gases. 

The  first  lachrymator  used  was  a  mixture  of  the  chlorides 
and  bromides  of  toluene.  Benzyl  chloride  and  bromide  are 
the  only  valuable  substances  in  this  mixture,  the  higher 
halogenated  products  having  little  or  no  lachrymatory  value. 
Xylyl  bromide  is  also  effective.  Chloroacetone  and  bromoace- 
tone  are  also  well  known  lachrymators,  though  they  are  expen- 
sive to  manufacture  and  are  none  too  stable.  Because  of  this 
the  French  modified  their  preparation  and  obtained  mixtures 
to  which  they  gave  the  name  ''martonite."  This  is  a  mixture 
of  80  per  cent  bromoacetone  and  20  per  cent  chloroacetone,  and 
can  be  made  with  nearly  complete  utilization  of  the  halogen. 
Methyl  ethyl  ketone  may  also  be  used,  which  gives  rise  to 
the  ' '  homomartonite "  of  the  French.  During  the  early  part 
of  the  War,  when  bromine  was  so  very  expensive,  the  English 
developed  ethyl  ibdoacetate.  This  was  used  with  or  without 
the  addition  of  alcohol.  Later  the  French  developed  bromo- 
benzyl  cyanide,  C6H5CH(Br)CN.  This  was  probably  the  best 
lachrymator  developed  during  the  War  and  put  into  large  scale 
manufacture,  though  very  little  of  it  was  available  on  the 
field  of  battle  before  the  War  ended.  Chloroacetophenone 
would  have  played  an  important  part  had  the  War  continued. 

Disadvantage  of  Wave  Attacks 

As  will  be  discussed  more  fully  in  the  chapters  on  ''The 
Tactics  of  Gas,"  the  wave  attacks  became  relatively  less  im- 
portant in  1916  through  the  use  of  gas  in  artillery  shell.  This 
was  the  result  of  many  factors.  Cloud  gas  attacks,  as  carried 
out  under  the  old  conditions,  required  a  long  time  for  the 
preliminary  preparations,  entailed  a  great  deal  of  labor  under 
the  most  difficult  conditions,  and  were  dangerous  of  execution 
even  when  weather  conditions  became  suitable.  The  difficulties 
may  be  summarized  as  follows: 

(1)  The  heavy  gas  cylinders  used  required  a  great  deal  of 
transportation,  and  not  only  took  the  time  of  the  Infantry  but 
rendered    surprise    attacks    difficult    owing    both    to '  the    time 


MODERN  DEVELOPMENT  OF  GAS  WARFARE  17 

required  and  to  the  unusual  activity  behind  the  lines  that  became, 
Avith  the  development  of  aeroplanes,  more  and  more  readily 
discerned. 

(2)  Few  gases  were  available  for  wave  attacks — chlorine, 
phosgene  and,  to  a  less  extent,  chloropicrin  proving  to  be  the  only 
ones  successfully  used  by  either  the  Allies  or  the  Germans. 
Hydrogen  sulfide,  carbon  monoxide  and  hydrocyanic  acid  gas 
were  suggested  and  tried,  but  were  abandoned  for  one  reason  or 
another. 

(3)  Gas  cloud  attacks  were  wholly  dependent  upon  weather 
conditions.    Not  only  were  the  velocity  and  direction  of  the  wind 
highly  important  as  regards  the  successful  carrying  of  the  wave 
over  the  enemy's  line,  but  also  to  prevent  danger  to  the  troops  \^ 
flaking  the  attack  due  to  a  possible  shift  of  the  wind,  which    © 
would  carry  the  gas  back  over  their  own  line. 

(4)  The  use  of  gas  in  artillery  shell  .does  not  require 
especially  trained  troops  inasmuch  as  gas  shell  are  fired  in  the 
same  manner  as  ordinary  shell,  and  by  the  same  gun  crews. 
Moreover,  since  artillery  gas  shell  are  used  generally  only  for 
ranges  of  a  mile  or  more,  the  direction  and  velocity  of  the  wind 
are  of  minor  importance.  Another  factor  which  adds  to  the 
advantage  of  artillery  shell  in  certain  cases  is  the  ability  to  land 
high  concentrations  of  gas  suddenly  upon  a  distant  target 
through  employing  a  large  number  of  the  largest  caliber  guns 
available  for  firing  gas. 

Notwithstanding  the  above  named  disadvantages  of  wave 
attacks  it  was  felt  by  the  Americans  from  the  beginning  that 
successful  gas  cloud  attacks  were  so  fruitful  in  producing 
casualties  and  were  such  a  strain  upon  those  opposed  to  it, 
that  they  would  continue.  Furthermore,  since  artillery  shell 
contain  about  10  per  cent  gas,  while  gas  cylinders  may  contain 
50  per  cent,  or  even  more  of  the  total  weight  of  the  cylinder, 
the  efficiency  of  a  cloud  gas  attack  for  at  least  the  first  mile 
of  the  enemy 's  territory  is  far  greater  than  that  of  the  artillery 
gas  attack.  It  was  accordingly  felt  tliat  the  only  thing  neces- 
sary to  make  cloud  gas  attacks  highly  useful  and  of  frequent 
occurrence  in  the  future  was  the  development  of  mobile 
methods — methods  whereby  the  gas  attack  could  be  launched 


18  CHEMICAL  WARFARE 

on  the  surface  of  the  ground  and  at  short  notice.  For  these 
reasons  gas  wave  attacks  may  be  expected  to  continue  and 
to  eventually  reach  a  place  of  very  decided  importance  in 
Chemical  Warfare. 

Gas  Shell 

The  firing  of  gas  in  artillery  ^hell  and  in  bombs  has  another 
great  advantage  over  the  wave  attack  just  mentioned.  There 
is  a  very  great  latitude  in  the  choice  of  those  gases  which 
have  a  high  boiling  point  or  which,  at  ordinary  temperatures, 
are  solids.  Mustard  gas  is  an  example  of  a  liquid  with  a  high 
boiling  point,  and  diphenylchloroarsine  an  example  of  a  gas 
that  is  ordinarily  solid.  For  the  above  reason  the  term  **gas 
warfare"  was  almost  a  misnomer  at  the  close  of  the  AVar,  and 
today  is  true  only  in  the  sense  that  all  the  substances  used 
are  in  a  gaseous  or  finely  divided  condition  immediately  after 
the  shell  explode  or  at  least  when  they  reach  the  enemy. 

Projector  Attacks 

Still  another  method  of  attack,  developed  by  the  British 
and  first  used  by  them  in  July,  1917,  was  the  projector  (in- 
vented by  Captain  Livens).  This  was  used  very  successfully 
up  to  the  close  of  the  War,  and,  though  the  German  attempted 
to  duplicate  it,  his  results  were  never  as  effective.  The  pro- 
jector consists  of  a  steel  tube  of  uniform  cross-section,  with 
an  internal  diameter  of  about  8  inches.  By  using  nickel  steel 
the  weight  may  be  decreased  until  it  is  a  one  man  load.  The 
projector  was  set  against  a  pressed  steel  base  plate  (about 
16  inches  in  diameter)  placed  in  a  very  shallow  trench. 

Until  about  the  close  of  the  war  projectors  were  installed 
by  digging  a  triangular  trench  deep  enough  to  bring  the 
muzzles  of  the  projectors  nearly  level  with  the  surface  of  the 
ground.  They  were  then  protected  by  sand  bags  or  canvas 
covers,  or  camouflaged  with  wire  netting  to  which  colored 
bits  of  cloth  were  tied  to  simulate  leaves  and  shadows.  The 
projectors  were  fired  by  connecting  them  in  series  with  ordinary 
blasting  machines  operated  by  hand  from  a  convenient  point 


MODERN  DEVELOPMENT  OF  GAS  WARFARE 


19 


in  the  rear.  The  digging  in  of  the  projectors  in  No  Man's 
Land  or  very  close  to  it  was  a  dangerous  and  laborious  under- 
taking. The  Americans  early  conceived  the  idea  that  pro- 
jectors could  be  fired  just  as  accurately  by  digging  a  shallow 
trench  just  deep  enough  to  form  a  support  for  the  base  plate, 
and  then  supporting  the  outer  ends  of  the  projector  on  crossed 


'            mi '^"&^'^^-i''^dM^' 

''  0 

**    ■    ?^• 

Jfl^^^^^Hj 

^ 

iCi 

^r  %     \ 

*»*                   • 

Fig.  2. — Livens'  Projector. 

The  Type  shown  is  an  18  cm.  German  Gas  Projector,  captured  during  the  2d  Battle 

of  the  Mar ne. 


sticks  or  a  light  frame  work  of  boards.  This  idea  proved 
entirely  practical  except  for  one  condition.  It  was  found 
necessary  to  fire  with  a  single  battery  all  the  projectors  near 
enough  together  to  be  disturbed  by  the  blast  from  any  portion 
of  them.  ^  Inasmuch  as  most  of  the  blasting  machines  used  for 
firing  had  a  capacity  of  only  20  to  30  projectors,  it  was  neces- 
sary to  so  greatly  scatter  a  large  projector  attack  that  the 


20  CHEMICAL  WARFARE 

method  was  very  little  used.  However,  investigations  were 
well  under  way  at  the  close  of  the  War  to  develop  portable 
firing  batteries  that  would  enable  the  discharge  of  at  least 
100  and  preferably  500  projectors  at  one  time.  By  this  arrange- 
ment a  projector  attack  could  be  prepared  and  launched  in 
two  to  four  hours,  depending  upon  the  number  of  men  avail- 
able. This  enabled  the  attack  to  be  decided  upon  in  the 
evening  (if  the  weather  conditions  were  right),  and  to  have 
the  attack  launched  before  morning,  thereby  making  it  impos- 
sible for  aeroplane  observers,  armed  with  cameras,  to  discover 
the  preparation  for  the  projector  attack.  Since  the  bombs 
used  in  the  projector  may  carry  as  high  as  30  pounds  of  gas 
(usually  phosgene),  some  idea  of  the  amount  of  destruction 
may  be  gained  when  it  is  known  that  the  British  fired  nearly 
2500  at  one  time  into  Lens. 

Stokes'  Mortar 

Another  British  invention  is  the  Stokes'  gun  or  trench 
mortar.  The  range  of  this  gun  is  about  800  to  1000  yards. 
It  is  therefore  effective  only  where  the  front  lines  are  rela- 
tively close  together.  The  shell  consists  of  a  case  containing 
the  high  explosive,  smoke  material  or  gas,  fitted  to  a  base 
filled  with  a  high  charge  of  propelling  powder.  The  shell  is 
simply  dropped  into  the  gun.  At  the  bottom  of  the  gun  there 
is  a  projection  or  stud  that  strikes  the  primer,  setting 
off  the  small  charge  and  expelling  the  projectile.  In  order 
to  obtain  any  considerable  concentration  of  gas  in  a  particular 
locality,  it  is  necessary  to  fire  the  Stokes'  continuously  (15 
shots  per  minute  being  possible  under  battle  conditions)  for  two 
to  five  minutes  since  the  bomb  contains  only  seven  pounds  of  gas. 

SUPERPALITE 

It  is  believed  that  the  first  gas  shell  contained  lachrymators 
or  tear  gases.  Although  the  use  of  these  shell  continued  up 
to  and  even  after  the  introduction  of  mustard  gas,  they  gradu- 
ally fell  off  in  number — the  true  poison  gas  shell  taking  their 
place.    Towards  the  end  of  1915  Auld  states  that  the  Germans 


MODERN  DEVELOPMENT  OF  GAS  WARFARE  21 

were  using  chloromethyl  chloroformate  (palite)  in  shell.  In 
1916,  during  the  battle  of  the  Somme,  palite  was  replaced  by 
superpalite  (trichloromethyl  chloroformate,  or  diphosgene) 
which  is  more  toxic  than  palite,  and  about  as  toxic  as  phosgene. 
It  has  the  advantage  over  phosgene  of  being  much  more  per- 
sistent. In  spite  of  the  fact  that  American  chemists  were  not 
able  to  manufacture  superpalite  on  a  large  scale,  or  at  least 


Fig.  3.-    .Stokes'  ^lortur. 

SO  successfully  that  it  would  compete  in  price  with  other  Avar 
gases,  the  Germans  used  large  quantities  of  it,  alone  and 
mixed  with  chloropierin,  in  shell  of  every  caliber  up  to  and 
including  the  15  cm.  Howitzer. 

Chloropicrin       \ 

The  next  gas  to  be  introduced  was  chloropicrin,  trichloro- 
nitromethane  or  ''vomiting  gas."  It  has  been  stated  that 
a  mixture  of  chloropicrin  (25  per  cent)  and  chlorine  (75  per 


22  CHEMICAL  WARFARE 

cent)  has  been  used  in  cloud  attacks,  but  the  high  boiling  point  of 
chloropicrin  (112°  C.)  makes  its  considerable  use  for  this  purpose 
very  unlikely.  The  gas  is  moderately  toxic  and  somewhat  lachry- 
matory, but  it  was  mainly  used  because  of  its  peculiar  property 
of  causing  vomiting  when  inhaled.  Its  value  was  further  in- 
creased at  first  because  it  was  particularly  difficult  to  prepare  a 
charcoal  which  would  absorb  it.  Its  peculiar  properties  are  apt 
to  cause  it  to  be  used  for  a  long  time. 

Sneezing  Gas 

During  the  summer  of  1917  two  new  and  very  important 
gases  were  introduced,  and,  as  before,  by  the  Germans.  One 
of  these  was  diphenylchloroarsine,  ''sneezing  gas"  or  ''Blue 
Cross."  This  is  a  white  solid  which  was  placed  in  a  bottle 
and  embedded  in  TNT  in  the  shell.  Upon  explosion  of  the 
shell  the  solid  was  atomized  into  very  fine  particles.  Since  the 
ordinary  mask  does  not  remove  smoke  or  mists,  the  sneezing 
gas  penetrates  the  mask  and  causes  violent  sneezing.  The 
purpose,  of  course,  is  to  compel  the  removal  of  the  mask  in  an 
atmosphere  of  lethal  gas.  (The  firing  regulations  prescribed 
its  use  with  phosgene  or  other  lethal  shell.)  The  latest  type 
masks  protect  against  this  dust,  but  as  it  is  extraordinarily 
powerful,  its  use  will  continue. 

Mustard  Gas 

The  second  gas  was  dichloroethyl  sulfide,  mustard  gas, 
Yellow  Cross  or  Yperite,  Mustard  gas,  as  it  is  commonly 
designated,  is  probably  the  most  important  single  poisonous 
substance  used  in  gas  warfare.  It  was  first  used  by  the  Ger- 
mans at  Ypres,  July  12,  1917.  The  amount  of  this  gas  used 
is  illustrated  by  the  fact  that  at  Nieuport  more  than  50,000 
shell  were  fired  in  one  night,  some  of  which  contained  nearly 
three  gallons  of  the  liquid. 

Mustard  gas  is  a  high  boiling  and  very  persistent  material, 
which  is  characterized  by  its  vesicant  (skin  blistering)  action. 
Men  who  come  in  contact  with  it,  either  in  the  form  of  fine 
splashes  of  the  liquid  or  in  the  form  of  vapor,  suffer  severe 
blistering  of  the  skin.  The  burns  appear  from  four  to  twelve 
hours^after  exposure  and  heal  very  slowly.    Ordinary  clothing 


/ 


MODERN  DEVELOPMENT  OF  GAS  WARFARE  23 

is  no  protection  against  either  the  vapor  or  the  liquid.    Other 
effects  will  be  considered  in  Chapter  IX. 

Since  then  there  has  been  no  important  advance  so  far  as 
new  gases  are  concerned.  Various  arsenic  derivatives  were 
prepared  in  the  laboratory  and  tested  on  a  small  scale.  The 
Germans  did  actually  introduce  ethyldichloroarsine  and  the 
Americans  were  considering  methyldichloroarsine.  Attempts 
were  made  to  improve  upon  mustard  gas  but  they  were  not  suc- 
cessful. 

Lewisite 

It  is  rather  a  peculiar  fact  that  so  few  new  chemical  com- 
pounds  were  used  as  war  gases.  Praxrdcally  all  X^e. substances 
were  well  known  to  tbe^  organic,  chemist  .lQn^_bef ore  the_ World 
War.  One  of  the  most  interesting  and  valuable  of  the  compounds 
which  would  have  found  extensive  use  had  the  War  continued,  is 
an  arsenic  compound  called  Lewisite  from  its  discoverer,  Capt. 
W.  Lee  Lewis,  of  Northwestern  University.  The  chemistry  of 
this  compound  is  discussed  in  Chapter  X.  Because  of  the  early 
recognized  value  of  this  compound,  very  careful  secrecy  was 
maintained  as  to  all  details  of  the  method  of  preparation  and  its 
properties.  As  a  result,  strange  stories  were  circulated  about  its 
deadly  powers.  Characteristic  of  these  was  the  story  that 
appeared  in  the  New  York  Times  early  in  1919.  Now  that  the 
English  have  published  the  chemical  and  pharmacological  prop- 
erties, we  can  say  that,  although  Lewisite  was  never  proven  on 
the  battle  field,  laboratory  tests  indicate  that  we  have  here  a  very 
powerful  agent.  Not  only  is  it  a  vesicant  of  about  the  same 
order  of  mustard  gas,  but  the  arsenical  penetrates  the  skin  of  an 
animal,  and  three  drops,  placed  on  the  abdomen  of  a  mouse,  are 
sufficient  to  kill  within  two  to  three  hours.  It  is  also  a  powerful 
respiratory  irritant  and  causes  violent  sneezing.  Its  possible  use 
in  aeroplane  bombs  has  led  General  Fries  to  apply  the  term 
' '  The  Dew  of  Death ' '  to  its  use  in  this  way. 

Camouflage  Gases        \ 

Considerable  effort  was  spent  on  the  question  of  camouflage 
gases.     This  involved  two  lines  of  research: 

(1)  To  prevent  the  recognition  of  a  gas  when  actually 
present  on  the  field,  by  masking  its  odor. 


CHEMICAL  WARFARE 


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28  CHEMICAL  WARFARE 

(2)  To  simulate  the  presence  of  a  toxic  gas.  This  may 
be  done  either  by  using  a  substance  whose  odor  in  the  field 
strongly  suggests  that  of  the  gas  in  question,  or  by  so  thor- 
oughly associating  a  totally  different  odor  with  a  particular 
**gas"  in  normal  use  that,  when  used  alone,  it  still  seems  to 
imply  the  presence  of  that  gas.  This  use  of  imitation  gas 
would  thus  be  of  service  in  economizing  the  use  of  actual 
''gas"  or  in  the  preparation  of  surprise  attacks. 

While  there  was  some  success  with  this  kind  of  ''gas," 
very  few  such  attacks  were  really  carried  out,  and  these  were 
in  connection  with  projector  attacks. 

Gases  Used 

Table  I  gives  a  list  of  all  the  gases  used  by  the  various 
armies,  the  nation  which  used  them,  the  effect  produced  and 
the  means  of  projection  used. 

Table  II  gives  the  properties  of  the  more  important  war 
cases  (compiled  by  Major  R.  E.  Wilson,  C.  W.  S.). 

The  gases  used  by  the  Germans  may  also  be  classified  by 
the  names  of  the  shell  in  which  they  were  used.  Table  III 
gives  such  a  classification. 

Markings  for  American  Shell 

In  selecting  markings  for  American  chemical  shell,  red  bands 
were  used  to  denote  persistency,  white  bands  to  denote  non- 
persistency  and  lethal  properties,  yellow  bands  to  denote  smoke, 
and  purple  bands  to  denote  incendiary  action.  The  number  of 
bands  indicates  the  relative  strength  of  the  property  indicated ; 
thus,  three  red  bands  denote  a  gas  more  persistent  than  one  red 
band. 

The  following  shell  markings  were  actually  used : 

1  White Diphenylchloroarsine 

2  White Phosgene 

1  White,  1  red Chloropicrin 

1  White,  1  red,  1  white 75%  Chloropicrin,  25%  Phosgene 

1  White,  1  red,  1  yellow 80%  Chloropicrin,  20%  Stannic  Chloride 

1  Red Bromoacetone 

2  Red Bromobenzylcyanide 

.  3  Red Mustard  Gas 

1  Yellow White  Phosphorus 

2  Yellow Titanium  Tetrachloride 


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TABLE  III 
German  Shell 


Name  of  Shell 

Shell  Filling 

Nature  of 
Effect 

B-shell  [Ki  shell  (White  B  or  BM)] 

Bromoketone     (B  r  o  m  o  - 
methylethyl  ketone) 

Lachrymator 

Blue  Cross  

(a)  Diphenylchloroarsine 
(6)  Diphenylcyanoarsine 
(r)   Diphenylchloroarsine, 
Ethyl  carbazol 

Sternutator 

C-shell  (Green  Cross)  (White  C) . . 

Superpalite 

Asphyxiant 

D-shell  (White  D) 

Phosgene 

(o)  SuperpaUte 
(6)  Phenyl  carbylamine 
chloride 

Lethal 

Green  Cross 

Asphyxiant 

Green  Cross  1 

Superpalite  65%, 
Chloropicrin  35% 

Asphyxiant 

Green  Cross  2 

Superpalite, 

Phosgene, 

Diphenylchloroarsine 

Asphyxiant 

Green  Cross  3  (Yellow  Cross  1) . . . 

Ethyldichloroarsine, 
Methyldibromoarsine, 
Dichloromethyl  ether 

Asphyxiant 

K-shell  (Yellow) 

Chloromethyl 

chloroformate  (Palite) 

Lachrymator 
AsphyTciant 

T-shell  (Black  or  green  T) 

Xylyl  bromide, 
Bromo  ketone 

Lachrymator 

Yellow  Cross 

Mustard  gas, 
Diluent  (CCI4,  CfiHsCl, 
CeHsNOa) 

Yellow  Cross  1. 

See  Green  Cross  3 

. 

CHAPTER   III 

DEVELOPMENT   OF   THE   CHEMICAL  WARFARE 
SERVICE  • 

Modern  chemical  warfare  dates  from  April  22, 1915.  Really, 
however,  it  may  be  said  to  have  started  somewhat  earlier,  for 
Germany  undoubtedly  had  spent  several  months  in  perfecting 
a  successful  gas  cylinder  and  a  method  of  attack.  The  Allies, 
surprised  by  such  a  method  of  warfare,  were  forced  to  develop, 
under  pressure,  a  method  of  defense,  and  then,  when  it  was 
finally  decided  to  retaliate,  a  method  of  gas  warfare.  '*  Offen- 
sive organizations  were  enrolled  in  the  Engineer  Corps  of  the 
two  armies  and  trained  for  the  purpose  of  using  poisonous 
gases;  the  first  operation  of  this  kind  was  carried  out  by  the 
British  at  the  battle  of  Loos  in  September,  1915. 

**  Shortly  after  this  the  British  Army  in  the  field  amal- 
gamated all  the  offensive,  defensive,  advisory  and  supply  activities 
connected  with  gas  warfare  and  formed  a  'Gas  Service'  with 
a  Brigadier  General  as  Director.  This  step  was  taken  almost 
as  a  matter  of  necessity,  and  because  of  the  continually  increas- 
ing importance  of  the  use  of  gas  in  the  war  (Auld)." 

At  once  the  accumulation  of  valuable  information  and  ex- 
perience was  started.  Later  this  was  very  willingly  and  freely 
placed  at  the  disposal  of  American  workers.  Too  much  cannot 
be  said  about  the  hearty  co-operation  of  England  and  France. 
Without  it  and  the  later  exchange  of  information  on  all  matters 
regarding  gas  warfare,  the  progress  of  gas  research  in  all  the 
allied  countries  would  have  been  very  much  retarded. 

While  many  branches  of  the  American  Army  were  engaged 
in  following  the  progress  of  the  war  during  1915-1916,  the 
growing  importance  of  gas  warfare  was  far  from  being  appre- 
ciated. When  the  United  States  declared  war  on  Germany 
April  6,  1917,  there  were  a  few  scattered  observations  on  gas 

31 


32  CHEMICAL  WARFARE 

warfare  in  various  offices'  of  the  different  branches,  but  there 
was  no  attempt  at  an  organized  survey  of  the  field,  while  abso- 
lutely no  effort  had  been  made  by  the  War  Department  to 
inaugurate  research  in  a  field  that  later  had  2,000  men  alone 
in  pure  research  work.  Equally  important  was  the  fact  that 
no  branch  of  the  Service  had  any  idea  of  the  practical  methods 
of  gas  warfare. 

The  only  man  who  seemed  to  have  the  vision  and  the  courage 
of  his  convictions  was  Van  H.  Manning,  Director  of  the  Bureau 
of  Mines.  Since  the  establishment  of  the  Bureau  in  1908  it 
had  maintained  a  staff  of  investigators  studying  poisonous  and 
explosive  gases  in  mines,  the  use  of  self-contained  breathing 
apparatus  for  exploring  mines  filled  with  noxious  gases,  the 
treatment  of  men  overcome  by  gas,  and  similar  problems.  At 
a  conference  of  the  Director  of  the  Bureau  with  his  Division 
Chiefs,  on  February  7,  1917,  the  matter  of  national  prepared- 
ness was  discussed,  and  especially  the  manner  in  which  the 
Bureau  could  be  of  most  immediate  assistance  with  its  per- 
sonnel and  equipment.  On  February  8,  the  Director  wrote 
C.  D.  Walcott,  Chairman  of  the  Military  Committee  of  the 
National  Research  Council,  pointing  out  that  the  Bureau  of 
Mines  could  immediately  assist  the  Navy  'and  the  Army  in 
developing,  for  naval  or  military  use,  special  oxygen  breathing 
apparatus  similar  to  that  used  in  mining.  He  also  stated  that 
the  Bureau  could  be  of  aid  in  testing  types  of  gas  masks  used 
on  the  fighting  lines,  and  had  available  testing  galleries  at  the 
Pittsburgh  experiment  station  and  an  experienced  staff.  Dr. 
Walcott  replied  on  February  12  that  he  was  bringing  the 
matter  to  the  attention  of  the  Military  Committee. 

A  meeting  was  arranged  between  the  Bureau  and  the  War 
College,  the  latter  organization  being  represented  by  Brigadier 
General  Kuhn  and  Major  L.  P.  Williamson.  At  this  conference 
the  War  Department  enthusiastically  accepted  the  offer  of  the 
Bureau  of  Mines  and  agreed  to  support  the  work  in  every 
way  possible. 

The  supervision  of  the  research  on  gases  was  offered  to 
Dr.  G.  A.  Burrell,  for  a  number  of  years  in  charge  of  the 
chemical  work  done  by  the  Bureau  in  connection  with  the 
investigation  of  mine  gases  and  natural   gas.     He  accepted 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE      33 

the  offer  on  April  7,  1917.  The  smoothness  with  which  the 
work  progressed  under  his  direction  and  the  importance  of 
the  results  obtained  were  the  result  of  Colonel  BuitcH's  great 
tact,  his  knowledge  of  every  branch  of  research  under  investi- 
gation and  his  imagination  and  general  broad-mindedness. 

Once,  however,  that  the  importance  of  gas  warfare  had  been 
brought  to  the  attention  of  the  chemists  of  the  country,  the 
response  waS  very  eager  and  soon  many  of  the  best  men  of  the 
university  and  industrial  plants  were  associated  with  Burrell 
in  all  the  phases  of  gas  research.  The  staff  grew  very  rapidly 
and  laboratories  were  started  at  various  points  in  the  East 
and  Middle  West. 

It  was  immediately  evident  that  there  should  be  a  central 
lal)oratory  in  Washington  to  co-ordinate  the  various  activities 
and  also  to  considerably  enlarge  those  activities  under  the 
joint  direction  of  tlie  Army,  the  Navy  and  the  Bureau  of 
Mines.  Fortunately  a  site  was  available  for  such  a  laboratory 
at  the  American  University,  the  use  of  the  buildings  and 
grounds  having  been  tendered  President  Wilson  on  April  30, 
1917.  Thus  originated  the  American  University  Experiment 
Station,  later  to  become  the  Research  Division  of  the  Chemical 
Warfare  Service. 

Meanwhile  otlier  organizations  were  getting  under  way. 
The  procurement  of  toxic  gases  and  the  filling  of  shell  was 
assigned  to  the  Trench  Warfare  Section  of  the  Ordnance 
Department.  In  June,  1917,  General  Crozier,  then  Chief  of 
the  Ordnance  Department,  approved  the  general  proposition 
of  building  a  suitable  plant  for  filling  shell  with  toxic  gas. 
In  November,  1917,  it  was  decided  to  establish  such  a  plant 
at  Gunpowder  Neck,  Maryland.  Owing  to  the  inability  of  the 
chemical  manufacturers  to  supply  the  necessary  toxic  gases, 
it  was  further  decided,  in  December,  1917,  to  erect  at  the  same 
place  such  chemical  plants  as  would  be  necessary  to  supply 
these  gases.  In  January,  1918,  the  name  was  changed  to  Edge- 
wood  Arsenal,  and  the  project  was  made  a  separate  Bureau 
of  the  Ordnance  Department,  Col.  William  H.  Walker,  of  the 
Massachusetts  Institute  of  Technology,  being  soon  afterwards  put 
in  command. 

While,  during  the  latter  part  of  the  War,  gas  shell  were 


34  CHEMICAL  WARFARE 

handled  by  the  regular  artillery,  special  troops  were  needed 
for  cylinder  attacks,  Stokes'  mortars.  Livens'  projectors  and 
for  other  forms  of  gas  warfare.  General  Pershing  early  cabled, 
asking  for  the  organization  and  training  of  such  troops,  and 
recommended  that  they  be  placed,  as  in  the  English  Army, 
under  the  jurisdiction  of  the  Engineer  Corps.  On  August  15, 
1917,  the  General  Staff  authorized  one  regiment  of  Gas  and 
Flame  troops,  which  was  designated  the  **30th  Engineers," 
and  was  commanded  by  Major  (later  Colonel)  E.  J.  Atkisson. 
This  later  became  the  First  Gas  Regiment,  of  the  Chemical 
Warfare  Service. 

About  this  time  (September,  1917)  the  need  of  gas  training 
was  recognized  by  the  organization  of  a  Field  Training  Section, 
under  the  direction  of  the  Sanitary  Corps,  Medical  Department. 
Later  it  was  recognized  that  neither  the  Training  Section  nor 
the  Divisional  Gas  Officers  should  be  under  the  Medical  Depart- 
ment, and,  in  January,  1918,  the  organization  was  transferred 
to  the  Engineer  Corps. 

All  of  these,  with  the  exception  of  the  Gas  and  Flame 
regiment,  were  for  service  on  this  side.  The  need  for  an  Over- 
seas force  was  recognized  and  definitely  stated  in  a  letter, 
dated  August  4,  1917.  On  September  3,  1917,  an  order  was 
issued  establishing  the  Gas  Service,  under  the  command  of 
Lt.  Col.  (later  Brigadier  General)  A.  A.  Fries,  as  a  separate 
Department  of  the  A.  E.  F.  in  France.  In  spite  of  a  cable 
on  September  26th,  in  which  General  Pershing  had  said 

"Send  at  once  chemical  laboratory,  complete  equipment  and  per- 
sonnel, inchiding  physiological  and  pathological  sections,  for  extensive 
investigation  of  gases  and  powders.  .  .  ." 

it  was  not  until  the  first  of  January,  1918,  that  Colonel  R.  F. 
Bacon  of  the  Mellon  Institute  sailed  for  France  with  about 
fifty  men  and  a  complete  laboratory  equipment. 

Meantime  a  Chemical  Service  Section  had  been  organized 
in  the  United  States.  This  holds  the  distinction  of  being  the 
first  recognition  of  chemistry  as  a  separate  branch  of  the 
military  service  in  any  country  or  any  war.  This  was  author- 
ized October  16,  1917,  and  was  to  consist  of  an  officer  of  the 
Engineers,  not  above  the  rank  of  colonel,  who  was  to  be 
Director  of  Gas  Service,  with  assistants,  not  above  the  rank 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE         35 

of  lieutenant  colonel  from  the  Ordnance  Department,  Medical 
Department  and  Chemical  Service  Section.  The  Section  itself 
was  to  consist  of  47  commissioned  and  95  non-commissioned 
officers  and  privates.  Colonel  C.  L.  Potter,  Corps  of  Engineers, 
was  appointed  Director  and  Professor  W.  H.  Walker  was  commis- 
sioned Lieutenant  Colonel  and  made  Assistant  Director  of  the 
Gas  Service  and  Chief  of  the  Chemical  Service  Section.  This  was 
increased  on  Feb.  15, 1918  to  227  commissioned  and  625  enlisted 
men,  and  on  May  6,  1918  to  393  commissioned  and  920  enlisted 
men.  Meanwhile  Lt.  Col.  Walker  had  been  transferred  to 
the  Ordnance  and  Lt.  Col.  Bogert  had  been  appointed  in  his 
place. 

At  this  time  practically  every  branch  of  the  Army  had  some 
connection  with  Gas  Warfare.  The  Medical  Corps  directed 
the  Gas  Defense  production.  Offense  production  was  in  the 
hands  of  the  Ordnance  Department.  Alarm  devices,  etc.,  were 
made  by  the  Signal  Corps.  The  Engineers  contributed  their 
30th  Regiment  (Gas  and  Flame)  and  the  Field  Training  Sec- 
tion. The  Research  Section  was  still  in  charge  of  the  Bureau 
of  Mines,  in  spite  of  repeated  attempts  to  militarize  it.  And 
in  addition,  the  Chemical  Service  Section  had  been  formed 
primarily  to  deal  with  overseas  work.  While  the  Director 
of  the  Gas  Service  was  expected  to  co-ordinate  all  these  activi- 
ties, he  was  given  no  authority  to  control  policy,  research  or 
production. 

In  order  to  improve  these  conditions  Major  General  Wm. 
L.  Sibert,  a  distinguished  Engineer  Officer  who  built  the  Gatun 
Locks  and  Dam  of  the  Panama  Canal  and  who  had  commanded 
the  First  Division  in  France,  was  appointed  Director  of  the 
Chemical  Warfare  Service  on  May  11,  1918.  Under  his  direc- 
tion the  Chemical  Warfare  Service  was  organized  with  the 
following  Divisions: 

Overseas Brigadier  General  Amos  A.  Fries 

Research Colonel  G.  A.  Burrell 

Development Colonel  F.  M.  Dorsey 

Gas  Defense  Production Colonel  Bradley  Dewey 

Gas  Offense  Production Colonel  Wm.  H.  Walker 

Medical Colond  W.  J.  Lyster 

Proving Lt.  Col.   W.  S.  Bacon 

Administration Brigadier  General  H.  C.  Newcomer 

Gas  and  Flame Colonel  E.  J.  Atkisson 


36  CHEMICAL  WARFARE 

The  final  personnel  authorized,  though  never  reached  owing 
to  the  signing  of  the  Armistice,  was  4,066  commissioned  officers 
and  44,615  enlisted  men;  this  was  including  three  gas  regi- 
ments of  eighteen  companies  each. 

General  Sibert  brought  with  him  not  only  an  extended 
experience  in  organizing  and  conducting  big  business,  but  a 
strong  sympathy  for  the  work  and  an  appreciation  of  the 
problem  that  the  American  Army  was  facing  in  France.  He 
very  quickly  welded  the  great  organization  of  the  Chemical 
Warfare  Service  into  a  whole,  and  saw  to  it  that  each  depart- 
ment not  only  carried  on  its  own  duties  but  co-operated  with 
the  others  in  carrying  out  the  larger  program,  which,  had  the 
war  continued,  would  have  beaten  the  German  at  his  ow^n 
game. 

More  detailed  accounts  will  now  be  given  of  the  various 
Divisions  of  the  Chemical  Warfare  Service. 

^-  Administration  Division 

The  Administration  Division  was  the  result  of  the  develop- 
ment which  has  been  sketched  in  the  preceding  pages.  It  is 
not  necessary  to  revicAV  that,  but  the  organization  as  of  October 
19,  1918  will  be  given: 

Director Major  General  Wm.  L.  Sibert 

Staff: 

Medical  Officer Colonel  W.  J.  Lyster 

Ordnance  Officer Lt.  Col.  C.  B.  Thurnrael 

British  Military  Mission Major  .J.  H.  Brightman 


A.ssistant  Director Colonel  H.  C.  N 


ewcomer 


Office  Administration Major  W.  W.  Parker 

Relations  Section Colonel  M.  T.  Bogert 

Personnel  Section Major  F.  E.  Breithut 

Contracts  and  Patents  Section Captain  W.  K.  Jackson 

Finance  Section Major  C.  C.  Coombs 

Requirements  and  Progress  Section. .  .  Capt.  S.  M.  Cadwell 

Confidential  Information  Section Major  S.  P.  Mullikin 

Transportation  Section Captain  H.  B,  Sharkey 

Training  Section . Lt.  Col.  G.  N.  Lewis 

Procurement  Section Lt.  Col.  W.  J.  Noonan 

The  administrative  offices  were  located  in  the  Medical 
Department  Building.  The  function  of  most  of  the  sections 
is  indicated  by  their  names. 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE  37 

The  Industrial  Relations  Section  was  created  to  care  for 
the  interests  of  the  industrial  plants  which  were  considered 
as  essential  war  industries.  Through  its  activity  many  vitally 
important  ii^dustries  were  enabled  to  retain,  on  deferred  classi- 
fication or  on  indefinite  furlough,  those  skilled  chemists  with- 
out which  they  could  not  have  maintained  a  maximum  output 
of  war  munitions. 

In  the  same  way  the  University  Relations  Section  cared 
for  the  educational  and  research  institutions.  In  this  way  our 
recruiting  stations  for  chemists  were  kept  in  as  active  operation 
as  war  conditions  permitted. 

Another  important  achievement  of  the  Administration  Sec- 
tion was  to  secure  the  order  from  The  Adjutant  General,  dated 
May  28,  1918,  that  read: 

"Owing  to  the  needs  of  tlie  mihtary  service  for  a  great  many 
men  trained  in  chemistry,  it  is  considered  most  important  that  all 
enlisted  men  who  are  graduate  chemists  should  be  assigned  to  duty 
where  their  special  knowledge  and  training  can  be  fully  utilized. 

"Enlisted  men  who  are  graduate  chemists  will  not  be  sent  overseas 
unless  they  are  to  be  emj  loved  on  chemical  duties.  .  .  ." 

While  this  undoubtedly  created  a  great  deal  of  feeling 
among  the  men  who  naturally  were  anxious  to  see  actual  fight- 
ing in  France,  it  was  very  important  that  this  order  be  carried 
out  in  order  to  conserve  our  chemical  strength.  The  following 
clipping  from  the  September,  1918,  issue  of  The  Journal  of 
Industrial  and  Engineering  Chemistry  shows  the  result  of  this 
order. 

"Chemists  in  Camp 

"As  the  result  of  the  letter  from  The  Adjutant  General  of  the 
Army,  dated  May  28,  1918,  1,749  chemists  have  been  reported  on. 
Of  these  the  report  of  action  to  August  1,  1918,  shows  that  281  were 
ordered  to  remain  with  their  military  organization  because  they  were 
already  performing  chemical  duties,  34  were  requested  to  remain  with 
their  military  organization  because  they  were  more  useful  in  the  military 
work  which  they  were  doing,  12  were  furloughed  back  to  industry, 
165  were  not  chemists  in  the  true  sense  of  the  word  and  were,  there- 


38  CHEMICAL  WARFARE 

fore,  ordered  back  to  the  line,  and  1,294  now  placed  in  actual  chemical 
work.  There  were  being  held  for  further  investigation  of  their  qualifica- 
tions on  August  1,  1918,  432  men.  The  remaining  23  men  were 
unavailable  for  transfer,  because  they  had  already  received  their  over- 
seas orders. 

"The  1,294  men,  who  would  otherwise  be  serving  in  a  purely  military 
capacity  and  whose  chemical  training  is  now  being  utilized  in  chemical 
work,  have,  therefore,  been  saved  from  waste. 

"Each  case  has  been  considered  individually,  the  man's  qualifications 
and  experience  have  been  studied  with  care,  the  needs  of  the  Govern- 
ment plants  and  bureaus  have  been  considered  with  equal  care,  and 
each  man  has  been  assigned  to  the  position  for  which  his  training 
and  qualifications  seem  to  fit  him  best. 

"Undoubtedly,  there  have  been  some  cases  in  which  square  pegs 
have  been  fitted  into  round  holes,  but,  on  the  whole,  it  is  felt  that  the 
adjustments  have  been  as  well  as  could  be  expected  under  the  cir- 
cumstances." 

Research  Division 

The  American  University  Experiment  Station,  established 
by  the  Bureau  of  Mines  in  April,  1917,  became  July  1,  1918 
the  Research  Division  of  the  Chemical  Warfare  Service.  For 
the  first  five  months  work  was  carried  out  in  various  labora- 
tories, scattered  over  the  country.  In  September,  1917,  the 
buildings  of  the  American  University  became  available ;  a  little 
later  portions  of  the  new  chemical  laboratory  of  the  Catholic 
University,  Washington,  were  taken  over.  Branch  laboratories 
were  established  in  many  of  the  laboratories  of  the  Universities 
and  industrial  plants,  of  which  Johns  Hopkins,  Princeton,  Yale, 
Ohio  State,  Massachusetts  Institute  of  Technology,  Harvard, 
Michigan,  Columbia,  Cornell,  Wisconsin,  Clark,  Bryn  Mawr, 
Nela  Park  and  the  National  Carbon  Company  were  active  all 
through  the  war. 

At  the  time  of  the  signing  of  the  armistice  the  organization 
of  the  Research  Division  was  as  follows : 

Col.  G.  A.  Burrell Chief  of  Research  Division 

Dr.  W.  K.  Lewis In  Charge  of  Defense  Problems 

Dr.  E.  P.  Kohler  i. In  Charge  of  Offense  Problems 

*  Succeeded  Dr.  John  Johnson  who  went  to  the  National  Research 
Council. 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE        39 

Dr.  Reid  Hunt Advisor  on  Pharmacological  Problems 

Lt.  Col.  W.  D.  Bancroft In  Charge  of  Editorial  Work  and  Cata- 

,  lytic  Research 

Lt.  Col.  A.  B.  Lamb  ^ In  Charge  of  Defense  Chemical  Re- 
search 
Dr.  L.  W.  Jones  ^ In  Charge  of  Offense  Chemical  Re- 
search 

Major  A.  C.  Fieldner In  Charge  of  Gas  Mask  Research 

Major  G.  A.  Richter In  Charge  of  Pyrotechnic  Research 

Capt.  E.  K.  Marshall ' In   Charge  of   Pharmacological   Re- 
search 

Dr.  A.  S.  Loevenhart ' In  Charge  of  Toxicological  Research 

Major  R.  C.  Tolman In  Charge  of  Dispersoid  Research 

Major  W.  S.  Rowland  * In  Charge  of  Small  Scale  Manufacture 

Major  B.  B.  Fogler  * In  Charge  of   Mechanical   Research 

and  Development 

Captain  G.  A.  Rankin In  Charge  of  Explosive  Research 

Major  Richmond  Levering In  Charge  of  Administration  Section 

The  chief  functions  of  the  Research  Division  were: 

1.  To  prepare  and  test  compounds  which  might  be  of  value  in 
gas  warfare,  determining  the  properties  of  these  substances  and 
the  conditions  under  which  they  might  be  effective  in  warfare. 

2.  To  develop  satisfactory  methods  of  making  such  .com- 
pounds as  seemed  promising  (Small  Scale). 

*At  first  Lt.  Col.  J.  F.  Norris  was  in  charge  of  all  chemical  research. 
About  December,  1917,  it  was  divided  into  Offense  and  Defense,  and  Lt. 
Col.  Lamb  was  placed  in  charge  of  Defense.  When  Col.  Norris  went  to 
England  as  Liaison  Officer,  Dr.  Jones  took  his  place. 

"  In  the  early  organization  of  the  Bureau  of  Mines,  Dr.  Yandall 
Henderson  was  in  charge  of  the  Medical  Sciences.  Associated  with  him 
were  Dr.  F.  P.  Underhill,  in  charge  of  Therapeutic  Research;  Major  M.  C. 
Winternitz,  in  Charge  of  Pathological  Research  and  Captain  E.  K.  Marshall 
in  charge  of  Pharmacological  Research.  About  May  1,  1918,  Phar- 
macological Research  became  so  extensive  that  the  Section  was  made  into 
two,  with  Marshall  and  Loevenhart  in  charge,  while  Dr.  Hunt  was  appointed 
special  adviser  on  pharmacological  problems.  When  the  transfer  to  the 
War  Department  was  made,  Henderson,  Underhill,  Winternitz  and  Marshall 
were  transferred  to  the  Medical  Division. 

*Lt.  Col.  McPherson  was  formerly  in  charge,  and  was  later  transferred 
to  Ordnance. 

"  This  Section  was  originally  under  H.  H.  Clark.  Later  it  was  split 
into  two,  with  Clark  and  Fogler  in  charge,  and  finally  consolidated  under 
Fogler. 


.40 


CHEMICAL  WARFARE 


3.  To  develop  the  best  methods  of  utilizing  these  compounds. 

4.  To  develop  materials  which  should  absorb  or  destroy  war 
gases,  studying  their  properties  and  determining  the  conditions 
under  which  they  might  be  effective. 

5.  To  develop  satisfactory  methods  of  making  such  absorbents 
as  might  seem  promising. 

6.  To  develop  masks,  canisters,  protective  clothing,  etc. 

7.  To  develop  incendiaries,  smokes,  signals,  etc.,  and  the  best 
methods  of  using  the  same. 


m 

^    t^*^i 

^3H 

/^^Bl 

Fig.   4. — American    University   Experiment   Station,    showing   Small   Scale 

Plants. 


8.  To  co-operate  with  the  manufacturing  divisions  in  regard 
to  difficulties  arising  during  the  operations  of  manufacturing  war 
gases,  absorbents,  etc. 

9.  To  co-operate  with  other  branches  of  the  Government,  civil 
and  military,  in  regard  to  war  problems. 

10.  To  collect  and  make  available  to  the  Director  of  the 
Chemical  Warfare  Service  all  information  in  regard  to  the 
chemistry  of  gas  warfare. 

The  relation  of  the  various  sections  may  best  be  shown 
by  outlining  the  general  procedure  used  when  a  new  toxic 
substance  was  developed. 

The   substance   in  question  may   have   been  used  by  the 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE         41 

Germans  or  the  Allies;  it  may  have  been  suggested  by  someone 
outside  the^  station;  or  the  staff  may  have  thought  of  it  from 
a  search  of  the  literature,  from  analogy  or  from  pure  inspira- 
tion. The  Offense  Research  Section  made  the  substance.  If  it 
was  a  solid  it  was  sent  to  the  Dispersoid  Section,  where  methods 
of  dispersing  it  were  worked  out.  When  this  had  been  done, 
or,  at  once,  if  the  compound  was  a  liquid  or  vapor,  it  was  sent 
to  the  Toxicological  Section  to  be  tested  for  toxicity,  lachry- 
matory power,  vesicant  action,  or  other  special  properties.  If 
these  tests  proved  the  compound  to  have  a  high  toxicity  or 
a  peculiar  physiological  behavior,  it  was  then  turned  over 
to  a  number  of  different  sections. 

The  Offense  Research  Section  tried  to  improve  the  method 
of  preparation.  When  a  satisfactory  method  had  been  found, 
the  Chemical  Production  or  Small  Scale  Manufacturing  Section 
endeavored  to  make  it  on  a  large  scale  (50  pounds  to  a  ton) 
and  worked  out  the  manufacturing  difficulties.  If  further 
tests  showed  that  the  substance  was  valuable,  the  manufacture 
was  then  given  to  the  Development  Division  or  the  Gas  Offense 
Production  Division  for  large  scale  production. 

Meanwhile  the  Analytical  Section  had  been  working  on  a 
method  for  testing  the  purity  of  the  material  and  for  analyzing 
air  mixtures,  and  the  Gas  Mask  Section  had  run  tests  against 
it  with  the  standard  canisters.  If  the  protection  afforded  did 
not  seem  sufficient,  the  Defense  Chemical  Section  studied 
changes  in  the  ingredients  of  the  canister  or  even  developed 
a  new  absorbent  or  mixture  of  absorbents  to  meet  the  emergency. 
If  a  change  in  the  mechanical  construction  of  the  canister  was 
necessary,  this  was  referred  to  the  Mechanical  Research  Sec- 
tion ;.  this  work  was  especially  important  in  case  the  material 
was  to  be  used  as  a  toxic  smoke. 

The  compound  was  also  sent  to  the  Pyrotechnic  Section, 
which  studied  its  behavior  when  fired  from  a  shell,  or,  if 
suitable,  when  used  in  a  cylinder.  If  it  proved  stable  on 
detonation,  large  field  tests  were  then  made  by  the  Proving 
Division,  in  connection  with  tlie  Pyrotechnic  and  Toxicological 
Sections  of  the  Research  Division,  to  learn  the  effect  when 
shell  loaded  with  the  compound  were  fired  from  g-uns  on  a 
range,  with  animals  placed  suitably  in  or  near  the  trenches. 


42  CHEMICAL   WARFARE 

The  Analytical  Section  worked  out  methods  of  detecting  the 
gas  in  the  field,  wherever  possible. 

The  Medical  Division,  working  with  the  Toxicological  and 
Pharmacological  Sections,  studied  pathological  details,  methods 
of  treating  gassed  cases,  the  effect  of  the  gas  on  the  body, 
and  in  some  cases  even  considered  other  questions,  such  as 
the  susceptibility  of  different  men. 

If  the  question  of  an  ointment  or  clothing  entered  into  the 
matter  of  protection,  these  were  usually  attacked  by  several 
Sections  from  different  points  of  view. 

Out  of  the  250  gases  prepared  by  the  Offense  Chemical 
Research  Section,  very  few  were  sufficiently  valuable  to  pass  all  of 
these  tests  and  thus  the  number  of  gases  actually  put  into  large 
scale  production  were  less  than  a  dozen.  This  had  its  advan- 
tages, for  it  made  unnecessary  a  large  number  of  factories 
and  the  training  of  men  in  the  manufacturing  details  of  many 
gases.  As  one  British  report  stated,  ''The  ultimate  object  of 
chemical  warfare  should  be  to  produce  two  substances  only; 
one  persistent  and  the  other  non-persistent;  both  should  be 
lethal  and  both  should  be  penetrants. '  *  They  might  well  have 
added  that  both  should  be  instantly  and  powerfully  lachry- 
matory. 

Since  most  of  the  work  of  the  Research  Division  will  be 
covered  in  detail  in  later  chapters,  only  a  brief  summary  of 
the  principal  problems  will  be  given  here. 

The  first  and  most  important  problem  was  the  development 
of  a  gas  mask.  This  was  before  Sections  had  been  organized 
and  was  the  work  of  the  entire  Division.  After  comparing  the 
existing  types  of  masks  it  was  decided  that  the  Standard 
Box  Respirator  of  the  British  was  the  best  one  to  copy.  Because 
we  were  entirely  new  at  the  game  that  meant  work  on  char- 
coal, soda  lime,  and  the  various  mechanical  parts  of  the  mask, 
such  as  the  facepiece,  elastics,  eyepieces,  mouthpiece,  nose- 
clip,  hose,  can,  valves,  etc.  The  story  of  the  ''first  twenty- 
thousand"  is  very  well  told  by  Colonel  Burrell.^ 

^J.  Ind.  Eng.  Chem.,  11,  93   (1919). 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE       43 


"The  First  Twenty  Thousand 

"About  the  first  of  May,  1917,  Major  L.  P.  Williamson,  acting  as 
liaison  oflficer  between  the  Bureau  of  Mines  and  the  War  Department, 
put  the  last  ounce  of  *pep'  into  the  organization  by  asking  us  to 
build  20,000  gas  masks  for  shipment  overseas.  20,000  masks  did  not 
seem  like  a  very  large  order.  We  did  not  fully  appreciate  all  the 
conditions  which  a  war  gas  mask  had  to  encounter,  so  we  readily  and 
willingly  accepted  the  order.  Then  began  a  struggle  with  can  manu- 
facturers, buckle  makers,  manufacturers  of  straps,  rubber  facepieces, 
eyepieces,  knapsacks,  etc.  The  country  w^as  canvassed  from  the  Atlantic 
Coast  to  the  Mississippi  River  for  manufacturers  who  could  turn  out 
the  different  parts  acceptably  and  in  a  hurry. 

"Charcoal  was  made  from  red  cedar  by  the  Day  Chemical  Co.  of 
Westline,  Pennsylvania;  soda-lime  permanganate  was  manufactured 
by  the  General  Chemical  Company;  knapsacks  by  the  Simmons  Hard- 
ware Company  in  St.  Louis;  facepieces  by  the  Goodrich  and  Goodyear 
Rubber  Companies  at  Akron;  canisters  by  the  American  Can  Com- 
pany; and  the  assembly  made  at  one  of  the  plants  of  the  American 
Can  Company  in  Long  Island  City.  . 

"The  writer  cannot  recall  all  the  doubts,  fears,  optimism,  and 
enthusiasm  felt  in  turn  by  different  members  of  the  organization 
during  the  fabrication  of  those  first  20,000  masks.  We  were  performing 
an  important  task  for  the  War  Department.  Night  became  day.  Dewey, 
Lewis,  Henderson,  Gibbs,  and  others  stepped  from  one  train  to  another, 
and  we  used  the  telephone  between  Washington  and  St.  Louis  or 
Boston  as  freely  as  we  used  the  local  Washington  telephone. 

"We  thought  we  could  improve  on  the  English  box  respirator  on 
various  points.  We  made  the  canister  larger,  and  have  been  glad 
ever  since  that  we  did.  We  thought  the  English  mouthpiece  was  too 
flexible  and  too  small,  and  made  ours  stiff  and  larger,  and  were  sorry 
we  made  the  change.  We  tested  the  fillings  against  chlorine,  phosgene, 
prussic  acid,  etc.,  and  had  a  canister  that  was  all  that  was  desired 
for  absorbing  these  gases.  But,  alas,  we  did  not  know  that  chloropicrin 
was  destined  to  be  one  of  the  most  important  war  gases  used  by  the 
various  belligerents.  Further,  it  was  not  fully  appreciated  that  the 
rubberized  cloth  used  in  making  the  facepiece  had  to  be  highly  imperme- 
able against  gases,  that  hardness  as  much  as  anything  else  was  desired 
in  the  make-up  of  the  soda-lime  granules  in  order  to  withstand  rough 
jolting  so  that  the  fines  would  not  clog  the  canister,  and  raise  the 
resistance  to  breathing  to  a  prohibitive  figure.  Neither  was  it  appre- 
ciated at  that  time  by  any  of  the  allies,  that  the  gas  mask  really  should 


44  CHEMICAL  WARFARE 

be  a  fighting  instrument,  one  that  men  could  work  hard  in,  run  in, 
and  wear  for  hours,  without  too  serious  discomfort. 

"The  first  20,000  masks  sent  over  to  England  were  completed  by 
the  Research  Division  in  record  time.  As  compared  with  the  French 
masks,  they  were  far  superior,  giving  greater  ijroteetion  against  chlorine, 
phosgene,  superpalite,  prussic  acid,  xylyl  bromide,  etc.  The  French 
mask  was  of  the  cloth  type,  conforming  to  the  face,  and  consisting 
of  twenty  layers  of  cheesecloth  impregnated  with  sodium  phenate  and 
hexamethylenetetramine.  Chloropicrin  went  through  this  like  a  shot. 
Just  before  the  masks  were  sent  abroad,  we  received  disturbing  rumors 
of  the  contemplated  use  of  large  quantities  of  chloropicrin.  The  French, 
apparently,  had  no  intention  of  changing  the  design  of  their  mask, 
and  did  not  do  so  for  months  to  come.  We  therefore  released  the 
masks,  they  were  sent  abroad,  and  an  anxious  research  group  on 
this  side  of  the  water  waited  expectantly  for  the  verdict.  It  came. 
A  brief  cablegram  told  us  what  our  English  cousins  thought  .of  us. 
It  was  a  subject  they  had  been  wrestling  with  for  two  years  and 
a  half.  They  had  had  battlefield  experience;  they  had  gone  through 
the  grief  of  developing  poor  masks  into  better  ones,  knew  the  story 
better  than  we  did,  and  after  a  thorough  test  'hammered'  the  American 
design  unmercifully. 

"This  experience  put  the  Research  Division  on  its  mettle.  Our  first 
attempt  had  given  us  the  necessary  preliminary  experience;  cablegrams 
and  reports  traveled  back  and  forth;  an  expert  or  two  eventually  came 
to  this  country  from  England  in  response  to  previous  appeals  for 
assistance,  and  we  turned  with  adequate  infoimation  to  the  develop- 
ment of  a  real  mask." 

The  story  of  mustard  gas  is  given  later.  It  probably 
occupied  more  time  and  thought  on  the  part  of  the  Research 
Division,  as  well  as  that  of  Edgewood  Arsenal  and  the  Develop- 
ment Division,  than  any  other  gas. 

Diphenylchloroarsine  led  to  the  preparation  of  a  series  of 
arsenic  compounds,  some  more  easily  prepared  and  more  or 
less  effective.  ._^ 

Cyanogen  chloride  and  cyanogen  bromide,  reported  by  the 
Italians  as  having  been  used  by  the  Germans,  were  extensively 
studied. 

The  Inorganic  Section  was  early  interested  iff  special  in- 
cendiary materials  which  were  developed  for  bombs,  shells, 
darts  and  grenades,  and  which  were  later  taken  over  by  the 


^^^^IJE] 


VELOPMENT  OF  CHEMICAL  WARFARE  SERVICE        45 

Pyrotechnic  Section,  and  finally  adopted  by  the  Ordnance 
Department. 

In  discussing  the  work  one  can  very  well  start  with  the 
'Offense  Section.  This  Section  had  two  aims  in  view  always, 
to  develop  methods  of  making  the  gases  used  by  the  Germans 
more  economically  than  they  were  making  them,  and  to  develop 
better  gases  if  possible.  Wlien  we  entered  the  war,  chlorine, 
phosgene  and  choloropicrin  were  the  lethal  gases  used,  while 
bromoacetone  and  xylyl  bromide  were  the  lachrymators.  It  was 
not  a  difficult  matter  to  prepare  these.  But  the  introduction 
of  mustard  gas  in  the  summer  of  1917  and  of  diphenylchloro- 
arsine  in  the  autumn  of  the  same  year,  not  only  made  our 
chemists  ponder  over  a  manufacturing  method,  but  also  so 
revised  our  notions  of  warfare  that  the  possibility  of  using 
other  substances  created  the  need  for  extensive  research.  The 
development  of  bromobenzylcyanide  by  the  French  likewise 
opened  a  new  field  among  lachrymatory  substances. 

Colored  rockets  and  smokes  were  developed  for  the  Navy 
and  Army.  The  smoke  box  was  also  studied  but  the  work 
was  taken  over  by  the  Pyrotechnic  Section. 

A  large  amount  of  pure  inorganic  research  on  arsine  and 
arsenides,  fluorine,  hydrofluoric  acid  and  fluorides,  cyanides, 
cyanogen  sulfide  and  nitrogen  tetroxide  was  carried  out, 
sometimes  successfully  and  at  other  times  with  little  or  no 
success. 

The  Analytical  Section  not  only  carried  out  all  routine 
analyses  but  developed  methods  for  many  new  gases. 

The  Offense  Section  worked  in  very  close  contact  with  the 
Small  Scale  Manufacturing  Section  (Chemical  Production 
Section).  Often  it  happened  that  a  method,  apparently  suc- 
cessful in  the  laboratory,  was  of  no  value  in  the  plant.  Small 
scale  plants  were  developed  for  mustard  gas,  hydrocyanic  acid, 
cyanogen  chloride,  arsenic  trichloride,  arsenic  trifluoride,  mag- 
nesium arsenide,  superpalite  and  bromobenzylcyanide. 

The  Chemical  Defense  Section,  organized  January,  1918, 
was  occupied  with  problems  relating  to  protection,  such  as 
charcoal,  soaa  lime,  and  special  absorbents,  eyepieces,  smoke 
filters,  efficiency  of  absorbents,  and  special  work  with  mustard 
gas. 


46  CHEMICAL  WARFARE 

Charcoal  demanded  extensive  research.  Raw  materials 
required  a  world-wide  search,  carbonizing  methods  had  to  be 
developed,  and  impregnating  agents  were  thoroughly  studied. 
This  story  is  told  in  Chapter  XIII. 

Soda  lime  was  likewise  a  difficult  problem.  Starting  with 
the  British  formula,  the  influence  of  the  various  factors  was 
studied  and  a  balance  between  a  number  of  desirable  qualities, 
absorptive  activity,  capacity,  hardness,  resistance  to  abrasion, 
chemical  stability,  etc.,  obtained.  The  final  product  consisted 
of  a  mixture  of  lime,  cement,  kieselguhr,  sodium  permanganate 
and  sodium  hydroxide. 

Equally  valuable  work  was  performed  in  the  perfection 
of  two  carbon  monoxide  absorbents  for  the  Navy.  The  better 
of  these  consisted  of  a  mixture  of  suitably  prepared  oxides 
which  acts  catalytically  under  certain  conditions,  and  causes 
the  carbon  monoxide  to  react  with  the  oxygen  of  the  air. 
Since  there  are  color  changes  connected  with  the  iodine  pen- 
toxide  reaction  (the  first  absorbent)  it  has  been  possible  to 
develop  this  so  as  to  serve  as  a  very  sensitive  detector  for 
the  presence  of  carbon  monoxide  in  air. 

While  the  question  of  smoke  filters  was  so  important  that 
it  occupied  the  attention  of  several  Sections,  the  Defense  Sec- 
tion developed,  as  a  part  of  its  work,  a  standard  method  of 
testing  and  comparing  filters,  and  did  a  great  deal  of  work 
on  the  preparation  of  paper  for  this  purpose. 

Various  problems  related  to  mustard  gas  were  also  studied. 
The  question  of  a  protective  ointment  was  solved  as  success- 
fully as  possible  under  the  circumstances,  but  was  dropped 
when  it  appeared  doubtful  if  under  battlefield  conditions  of  con- 
centration and  length  of  exposure,  any  ointment  offered  suffi- 
cient protection  to  pay  for  the  trouble  of  applying  it.  The 
removal  of  mustard  gas  from  clothing  was  investigated, 
especially  by  the  accelerating  effect  of  turkey  red  oil.  Another 
phase  of  the  work  concerned  the  destruction  of  mustard  gas 
on  the  ground,  while  a  fourth  phase  related  to  the  persistency 
of  mustard  (and  other  gases)  on  the  field  of  battle. 

The  Gas  Mask  Research  Section  concerned  itself  largely 
with  developing  methods  of  testing  canisters  and  with  routine 
tests.    When  one  considers  the  number  of  gases  studied  experi- 


DEVELOPMENT  OF  CHEMICAL   WARFARE  SERVICE       47 

mentally,  the  large  number  of  experimental  canisters  developed, 
all  of  which  were  tested  against  two  or  more  gases,  and  further 
that  the  Section  assisted  in  the  control  of  the  production  at  Long 
Island  City,  it  is  seen  that  this  was  no  small  job.  In  addition, 
the  effect  of  various  conditions,  such  as  temperature,  humidity, 
ageing,  size  of  particles,  were  studied  in  their  relation  to  the 
life  of  absorbents  and  canisters.  Man  tests  and  mechanical 
tests  will  be  discussed  in  a  later  chapter.  Other  studies  were 
concerned  with  weathering  tests  of  gas  mask  fabrics,  mustard 
gas  detector,  and  covering  for  dugout  entrances  (dugout 
blankets),  which  were  impregnated  with  a  mixture  of  mineral 
and  vegetable  oils.  In  studying  the  course  of  gases  through 
a  canister  the  'Svave  front"  method  was  of  great  value  in 
detecting  defects  in  canister  design  and  filling. 

The  Pyrotechnic  Section  was  composed  of  a  number  of 
units,  each  with  its  own  problem.  The  gas  shell  was  studied, 
with  special  reference  to  the  stability  of  gases  and  toxic  solids, 
both  on  storage  and  on  detonation.  Extensive  work  was  car- 
ried out  on  smoke  screens — a  Navy  funnel,  an  Army  portable 
smoke  apparatus,  using  silicon  tetrachloride,  a  grenade,  a 
Livens,  and  various  shell  being  developed  for  that  purpose. 
The  smoke  screen  was  adapted  to  the  tank  and  the  airplane 
as  well  as  to  the  funnel  of  a  ship.  Several  types  of  incendiary 
bombs  and  darts  were  perfected.  The  liquid  fire  gun  was 
studied  but  the  results  were  never  utilized  because  of  the 
abandonment  as  useless  of  that  form  of  warfare.  Various 
forms  of  signal  lights,  flares,  rockets  and  colored  smokes  were 
studied  and  in  most  cases  specifications  were  written.  Exten- 
sive studies  were  also  carried  out  on  gas  shell  linings,  from 
^vhich  a  lead  and  an  enamel  lining  were  evolved.  Many 
physical  properties  of  war  gases  and  their  mixtures  were 
determined. 

The  Dispersoid  Section  studied  the  production  of  smokes 
or  mists  from  various  solid  and  liquid  substances.  Apparatus 
were  developed  to  study  the  concentration  of  smoke  clouds 
and  their  rate  of  settling.  The  efficiency  of  various  filters  and 
canisters  was  determined,  and  among  other  things,  a  new  smoke 
candle  was  perfected. 

Mechanical  research  at  first  was  related  to  design  and  con- 


48  CHEMICAL  WARFARE 

struction  of  a  canister  and  mask,  based  on  the  English  type. 
During  the  latter  part  of  1917  the  Tissot  type  of  mask  was 
studied  and  then  turned  over  to  the  Gas  Defense  Division. 
A  Navy  Head  Mask  and  canister  was  perfected.  The  horse 
mask  was  developed  along  the  lines  of  the  British  type,  and 
also  a  dog  mask  of  the  same  general  nature.  Horse  boots  were 
also  constructed,  though  they  never  were  used  at  the  front. 
Many  Ordnance  and  Pyrotechnic  problems  were  also  success- 
fully completed,  not  the  least  of  which  was  a  noiseless  gas 
cylinder.  This  section  developed  the  first  special  poison  gas 
suit,  composed  of  an  oilcloth  suit,  a  mask  and  helmet  and  a 
special  canister. 

The  Manufacturing  Development  Section  had  general 
charge  of  the  defense  problems,  and  reaUy  acted  as  an  emer- 
gency section,  filling  in  as  occasion  demanded.  They  developed 
mustard  'gas  clothing  and  a  horse  mask.  They  constructed  a 
hydrogen  plant  at  Langley  Field,  assisted  in  solving  the  diffi- 
culties relating  to  Batchite  charcoal  at  Springfield,  Mass.,  and 
co-operated  in  the  study  of  paper  and  felt  as  filtering  materials 
for  smokes.  Towards  the  close  of  the  war  the  Section; was 
interested  in  the  application  of  the  gas  mask  to  the  industries. 

The  Physiological  work  is  discussed  under  the  Medical 
Division. 

The  Editorial  Section  received  reports  from  all  the  other 
Sections,  from  which  a  semi-monthly  report  was  written,  and 
distributed  to  authorized  representatives  of  the  Army  and 
Navy  and  to  our  Allies.  Reports  were  also  received  from 
abroad  and  the  information  thus  received  was  made  available 
to  the  Research  Division.  As  the  number  of  reports  increased 
the  work  was  collected  together  into  monographs  on  the  various 
war  gases,  absorbents,  smokes,  etc.  After  the  signing  of  the 
armistice  these  were  revised  and  increased  in  number,  so  that 
about  fifty  were  finally  turned  over  to  the  Director  of  the 
Chemical  Warfare  Service. 

Gas  Defense  Division 

The  story  of  the  Gas  Defense  Division  is  largely  the  story 
of  the  gas  mask.  Colonel  (then  Mr.)  Bradley  Dewey  was  in 
charge  of  the  "first  twenty  thousand.''     Soon  after  that  work 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE       49 

was  undertaken,  he  was  commissioned  Major  in  the  Gas  Defense 
Division  of  the  Sanitary  Corps  and  was  placed  in  charge  of  the 
entire  manufacturing  program.  The  work  of  the  Division 
included  the  development  and  manufacture  as  well  as  the  testing 
and  inspection  of  gas  masks,  and  other  defense  equipment.  The 
magnitude  of  the  work  is  seen  from  the  following  record  of  pro- 
duction :  5,692,000  completed  gas  masks,  3,614,925  of  which  were 


Fig.  5. — The  Defective  Gas  Mask. 

Successfully  us(;d  by  the  Gas  Defense  Division  to  stimulate  care  in  every  part  of  the 
operation  of  the  manufacture  of  Gas  Masks. 


produced  at  the  Long  Island  City  Plant,  while  the  remainder  were 
assembled  at  the  Hero  Manufacturing  Company's  Plant  at  Phila- 
delphia, 377,881  horse  masks,  191,388  dugout  blankets,  2,450  pro- 
tective suits  and  1,773  pairs  of  gloves,  1,246  tons  of  protective  oint- 
ment, 45,906  gas  warning  signals  (largely  hand  horns),  50,549 
trench  fans  and  many  oxygen  inhalators. 

The  story  of  the  ''first  twenty  thousand"  has  already  been 
told  on  page  43.    That  these  masks  were  far  from  satisfactory 


50  CHEMICAL  WARFARE 

is  no  reflection  upon  the  men  who  made  them.  Even  with 
tlie  standard  design  of  the  British  as  a  pattern,  it  was  impos- 
sible to  attain  all  the  knowledge  concerning  gas  masks  in  two 
months.  The  experience  gained  in  this  struggle  enabled  the 
Army  to  take  up  the  manufacture  of  gas  masks,  in  July,  1917, 
with  a  more  complete  realization  of  the  seriousness  of  the 
task.  The  masks  were  not  lost,  either,  for  they  were  sent  to 
the  various  camps  as  training  masks  and  served  a  very  useful 
purpose. 

The  first  order  after  this  was  for  1,100,000  masks,  to  be 
completed  within  a  year  from  date.  For  this  production  there 
was  authorized  one  major,  two  captains,  and  ten  lieutenants. 
How  little  the  problem  was  understood  is  evident  when  we 
realize  that  in  the  end  there  were  12,000  employees  in  the  Gas 
Defense  Plant  at  Long  Island  City,  N.  Y.  The  first  attempts  were 
to  secure  these  through  existing  concerns.  The  Hero  Manu- 
facturing Company  of  Philadelphia  undertook  the  work  and 
carried  on.  certain  portions  of  it  all  through  the  War.  Experi- 
ence soon  showed,  however,  that  because  oi  the  necessity  for 
extreme  care  in  the  manufacture  and  inspection  of  the  mask, 
the  ordinary  commercial  organization  was  not  adapted  to  carry 
on  their  manufacture  on  the  scale  necessitated  by  the  Army 
program.  Consequently,  on  NoY.  21,  1917,  the  Secretary  of 
"War  authorized  the  establishment  of  a  government  operated 
plant,  and  experienced  officials  were  drawn  from  New  York, 
Chicago,  Boston  and  other  manufacturing  centers  to  carry  on 
the  work.  Buildings  in  Long  Island  City,  not  far  from  the 
chemical  plant  (charcoal  and  soda  lime)  at  Astoria,  were  taken 
over  by  the  officers  of  the  Gas  Defense  Service,  until  in  July, 
1918,  five  large  buildings  were  occupied,  having  a  total  floor 
space  of  1,000,000  square  feet  (23  acres).  The  organization 
grew  from  the  original  thirteen  officers  until  it  included  some 
12,000  employees  of  whom  about  8,500  were  women.  Because 
of  the  care  required  in  all  the  work,  attempt  was  made  to 
secure,  as  far  as  possible,  those  who  had  relatives  with  the 
A.  E.  F.  The  thought  was  that  their  personal  interest  in 
the  work  would  result  in  greater  care  in  manufacture  and  inspec- 
tion.     The   personnel   was  unique   in   that   the   authority  was 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE        51 

apparently  divided  between  civilian  and  military,  but  there 
was  no  friction  because  of  this.  The  efficiency  of  the  entire 
organization  is  shown  by  the  fact  that  the  masks  manufactured 
at  Long  Island  City  cost  fifty  cents  less  per  mask  than  those  manu- 
factured under  contract. 

The  first  actual  shipment  (overseas)  of  box  respirators  was 
made  from  the  Gas  Defense  Plant  on  March  4,  1918.  From  this 
date  the  production  increased  by  leaps  and  bounds.  As  men- 
tioned above,  between  this  date  and  November  26,  when  the 
last  mask  was  manufactured,  3,146,413  masks  of  the  box 
respirator  type  were  passed  through  final  inspection  in  the 
plant.  The  greatest  daily  production,  43,926  masks,  was 
reached  on  October  26,  1918.  The  process  of  manufacture  will 
be  discussed  under  the  chapter  on  the  Gas  Mask. 

During  the  last  half  of  1918  the  Kops  Tissot  mask  was 
manufactured.  This  mask  had  been  perfected  during  the 
months  preceding  August,  1918,  when  its  manufacture  was 
started.  Considerable  difficulty  was  encountered  in  its  produc- 
tion, but  the  first  mask  was  completed  on  September  14,  and 
between  that  time  and  the  Armistice,  189,603  masks  of  this  type 
had  been  manufactured. 

Along  with  this  manufacturing  development  went  the  build- 
ing up  of  an  elaborate  procurement  force  charged  with  the 
responsibility  of  providing  parts  to  be  assembled  at  the  Gas 
Defense  Plant  and  at  the  Hero  Manufacturing  Company.  This 
Section  faced  a  hard  and  intricate  task,  but,  though  there  were 
instances  where  the  shortage  of  parts  temporarily  caused  a 
slowing  down  of  production,  these  were  remarkably  rare.  Not 
only  had  the  parts  to  be  standardized  and  specifications  writ- 
ten, but  a  field  inspection  force  had  to  be  trained  in  order 
that  the  finished  parts  might  be  suitable  for  the  final  assembly 
plant.  The  problem  was  further  complicated  by  the  fact  that 
the  design  was  constantly  changing,  as  improvement  followed 
improvement.  Officers,  trained  in  inspection  in  a  day,  were 
sent  out  to  train  inspectors  in  the  industrial  centers. 

In  February,  1918,  shortly  before  the  German  drive  com- 
menced, requisitions  were  received  for  sample  lots  of  oiled 
mittens  and  oiled  union  suits  as  protection  against  mustard 


52  CHEMICAL  WARFARE 

gas.  These  were  prepared  in  quantity  and  sent  to  the  front, 
as  was  also  a  considerable  amount  of  chloride  of  lime  for 
neutralizing  the  mustard  gas  in  the  field. 

Another  phase  of  the  work  consisted  of  the  Field  Testing 
Section,  which  was  organized  to  provide  field  testing  conditions 
for  the  regular  product  and  for  the  development  organization. 
Later  there  were  added  a  preliminary  course  of  training  for 
officers  for  overseas  duty  in  chemical  warfare,  the  military 
training  of  the  Gas  Defense  officers  located  in  and  near  New 
York  and  the  training  of  boat  crews  engaged  in  carrying 
offensive  gas  supplies.  The  Field  Testing  Section  rendered  valu- 
able service  in  pointing  out  weaknesses  of  designs  as  develop- 
ments took  place  and  especially  those  uncomfortable  features 
of  the  masks  which  were  apparent  only  through  long  wear. 
During  the  course  of  this  work  the  section  built  a  complete 
trench  system  in  the  Pennsylvania  Railroad  yards  with  an 
elaborate  dugout,  the  equal  of  any  of  the  famous  German 
quarters  on  the  Western  front. 

The  chapters  on  Charcoal,  Soda  Lime  and  the  Gas  Mask  must 
be  read  in  this  connection  to  gain  an  idea  of  the  work  carried 
out  by  this  Division.  It  is  summed  up  in  the  statement  that 
American  soldiers  were  provided  with  equipment  which  neu- 
tralized the  best  effects  of  German  chemical  knowledge  as 
evidenced  by  the  offensive  methods  and  materials  -  employed. 

The  organization  of  the  Gas  Defense  Division,  as  of  Nov.  11, 
1918,  was  as  follows : 


Colonel  Bradley  Dewey Officer  in  Charge 

Lieut.  Col.  A.  L.  Besse Asst.  Officer  in  Charge 

Major  M.  L.  Emerson Administration  Section 

Major  H.  P.  Schuit Comptrolling  Section 

Mr.  R.  Skemp Procurement  Section 

Major  C,  R.  Johnson Technical  Director 

Capt.  K.  Atterbury Field  Testing  Section 

Major  J.  C.  Woodruff Chemical    Manufacturing   and   Develop- 
ment 

Mr.  R.  R.  Richardson Manager,  Gas  Defense  Plant 

Capt.  H.  P.  Scott Officer  in  Charge,  Hero  Manufacturing  Co. 

Major  L.  W.  Cottman Engineering  Branch 

Major  T.  L.  Wheeler Chemical  Development 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICER        53 

Major  I.  W.  Wilson Astoria  Branch 

Capt.  W.  E.  Brophy San  Francisco  Branch 

Lt.  E.  J.  Noble Cleveland  Branch 

Lt.  L,  Merrill Springfield  Branch 

Edgewood  Arsenal 

The  Ordnance  Department,  in  making  plans  for  a  shell 
filling  plant,  thought  to  interest  existing  chemical  firms  in  the 
manufacture  of  the  required  toxic  materials.  As  plans  devel- 
oped, however,  difficulties  arose  in  carrying  out  this  program. 
The  manufacture  of  such  material  at  private  plants  necessitated 
its  shipment  to  the  filling  plant  at  Edgewood.  The  transporta- 
tion of  large  quantities  of  highly  toxic  gases  seemed  attended 
with  great  danger.  The  Director  General  of  Railroads  ruled 
that  all  such  shipments  must  be  made  by  special  train,  a  very 
expensive  method  of  transportation.  Still  more  serious  objec- 
tions were  encountered  in  the  attempt  to  enlist  the  co-operation 
of  existing  firms.  They  recognized  that  the  manufacture  of 
such  material  would  be  attended  by  very  great  danger;  that 
the  work  would  be  limited  to  the  duration  of  the  war;  and 
that  the  processes  involved,  as  well  as  the  plants  necessary 
for  carrying  out  their  processes,  would  have  little  post-war 
value.  Moreover,  such  firms  as  had  the  personnel  and  equip- 
ment were  already  over-worked.  With  a  few  exceptions 
(notably  the  American  Synthetic  Color  Company,  the  Oldbury 
Electro-Chemical  Co.,  Zinsser  &  Co.,  and  the  Dow  Chemical 
Company)  they  were  unwilling  to  undertake  work  of  this 
character  on  any  terms  whatever. 

Early  in  December,  1917,  therefore,  it  was  decided  to  erect, 
on  the  site  of  the  shell  filling  plant,  such  chemical  plants  as 
would  be  necessary  to  furnish  the  toxic  materials  required 
for  filling  the  shell.  The  Arsenal  is  situated  in  an  isolated 
district,  twenty  miles  east  of  Baltimore,  Maryland,  on  the 
Pennsylvania  Railroad,  and  comprises  3,400  acres.  Since  the 
main  line  of  the  Pennsylvania  Railroad  runs  on  one  side  of 
the  tract,  while  on  another  is  the  Bush  River,  only  a  few 
miles  from  its  mouth  in  Chesapeake  Bay,  the  tract  was  ideally 
situated  for  shipping.     This  site  was  referred  to,  at  first,  as 


54 


CHEMICAL  WARFARE 


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- 

DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE        55 

** Gunpowder  Reservation,"  but  on  May  4,  1918,  the  name  was 
officially  changed  to  **Edgewood  Arsenal." 

Some  idea  of  the  extent  of  the  work  may  be  gained  from 
the  following  facts.  On  October  1,  1918,  there  were  233  officers, 
6,948  enlisted  men  and  3,066  civilians  engaged  in  work  at  Edge- 
wood.  86  cantonments  were  built,  accommodating  about  8,500 
men,  while  the  five  officers'  barracks  provided  accommodations 
for  290.  The  completed  hospital  unit  consisted  of  34  buildings, 
accommodating  420  patients  und-er  ordinary  conditions.  The 
total  number  of  buildings  erected  on  the  Arsenal  grounds 
was  550.  14.8  miles  of  improved  roads  were  built,  and  21 
miles  of  standard  gauge  and  15  miles  of  narrow  gauge  railway. 
A  system  furnishing  9.5  millon  gallons  of  salt  water  and 
another  furnishing' two  millions  of  fresh  water  daily  were  suc- 
cessfully installed.  Large  power  plants  were  built  in  connec- 
tion with  the  shell  filling  plants  and  the  chlorine  plant. 

Plants  for  phosgene,  chloropicrin,  mustard  gas,  chlorine  and 
sulfur  chloride  were  built  and  placed  in  successful  operation. 
Most  of  the  raw  materials,  with  the  exception  of  sulfur  chloride, 
were  obtained  from  commercial  firms.  The  other  gases  and 
manufactured  materials  used,  such  as  phosphorus,  tin  and 
silicon  tetrachlorides,  bromobenzylcyanide  and  arsenic  deriva- 
tives were  supplied  by  various  plants  scattered  through  the 
East  and  Middle  West  States. 

The  raw  materials  used  by  the  Arsenal  in  1918  were  as 
follows : 


Salt 17,358,000  pounds 

Bleach 42,384,000       " 

Picric  acid 3,718,000       " 

Alcohol 3,718,000       " 

Sulfur 24,912,000       " 

Sulfur  chloride, 6,624,000       " 

Bromine 238,000       " 

Benzyl  chloride 26,000       " 

The  production  of  toxic  materials  and  the  amount  shipped 
overseas  in  bulk  follow: 


56 


CHEMICAL  WARFARE 


Production, 
Pounds 


Shipped  in 
Bulk,  Pounds 


Chlorine : 

Liquid 

Gaseous 

Chloropicrin 

Phosgene 

Mustard  gas 

Bromobenzyl  cyanide . 
White  phosphorus .... 

Tin  tetrachloride 

Titanium  tetrachloride 


5,446,000 
2,208,000 
5,552,000 
3,233,070 
1,422,000 
10,000 
2,012,000 
2,012,000 
362,000 


2,976,000 

3,806,000 
840,000 
380,000 

342,000 
212,000 


For  nearly  a  month  previous  to  the  signing  of  the  Armistice, 
the  various  plants  at  the  Arsenal  had  shut  down  or  were 
operated  only  to  an  extent  sufficient  to  maintain  the  machinery 
and  equipment  in  good  working  order,  on  account  of  the  lack 
of  shell  into  which  to  fill  the  gas,  so  that  the  above  figures 
do  not  at  all  represent  maximum  productive  capacity. 

These  plants  will  be  described  in  the  appropriate  chapters. 

The  shell  filling  plant  was  really  composed  of  several  small 
plants,  each  of  which  was  made  up  of  units  radiating  from  a 
central  refrigeration  plant  which  would  serve  all  the  units. 
Each  unit  could  then  be  fitted  with  machinery  adapted  for 
filling  shell  of  a  different  size,  and  for  a  particular  gas.  More- 
over, an  accident  in  one  of  the  units  would  in  no  way  impair 
the  working  of  the  remainder. 

The  problem  involved  in  the  filling  of  a  shell  with  toxic 
material  (which  is  always  a  liquid  or  a  solid  and  never  a  gas 
under  the  conditions  in  which  it  is  loaded  in  the  shell)  is  similar 
in  a  way  to  that  of  filling  bottles  with  carbonated  water.  In  the 
development  of  plans  for  the  filling  plant,  many  suggestions 
were  obtained  from  a  study  of  the  apparatus  used  in  com- 
mercial bottling  plants.  It  was  necessary  to  keep  in  mind  not 
only  the  large  number  of  shell  to  be  filled,  but  also  the  highly 
toxic  character  of  the  filling  material  to  be  used.  It  was  essen- 
tial that  the  work  of  filling  and  closing  the  shell  should  be 


I 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE        57 


clone  by  machinery  in  so  far  as  that  was  possible,  and  that 
the  operation  should  be  carried  out  in  a  thoroughly  ventilated 
room  or  tunnel,  arranged  so  that  the  machinery  contained  in 
the  tunnel  could  be  operated  from  the  outside.  Special  care 
was  taken  in  closing  the  shell,  the  closing  being  accomplished 
by  motors  actuated  by  compressed  air,  which,  in  the  closing 
process  were  driven  until  they  stalled.     In  this  way  a  uniform 


Fig.  7. — A  Typical  Shell-filling  Plant  at  Edgewood  Arsenal. 

closing  torque  was  obtained.  The  final  results  secured  were 
admirable,  as  is  evidenced  by  the  fact,  reported  by  the  Quarter- 
master Officer  at  Vincennes  on  November  15,  1918,  that  not 
a  single  leaky  shell  had  been  found  among  the  200,000  shell 
received  up  to  that  date. 

Details  of  the  filling  process  will  be  found  in  the  chapter 
on  Phosgene. 

Besides  the  ordinary  gas  filling  plants  (of  which  one  was 
completed  and  two  were  80  per  cent  completed)  there  was  a 


58 


CHEMICAL  WARFARE 


plant  for  stannic  chloride  grenades,  one  for  white  phosphorus 
grenades,  and  one  for  smoke  shell  also  filled  with  phosphorus 
and  a  plant  for  filling  incendiary  bombs. 

Shell  are  designated  by  their  diameter  in  inches  or  milli- 
meters. The  approximate  amount  of  toxic  gas  required  for 
filling  each  type  of  shell  (10.5  per  cent  void)  is  as  follows: 


Shell 

Phosgene, 
Pounds 

N.  C.,* 
Pounds 

Mustard  Gas, 
Pounds 

75  mm 

4 . 7  inch 

1.32 

4.27 

11.00 

22.00 

30.00 

1.75 

6.20 

15.40 

30.30 

1.35 
4.20  ' 

155  mm 

8  inch 

10.35 
21.60 

Livens 

*  N.C.  is  a  mixture  of  80  per  cent  chloropicrin  and  20  per  cent  stannic 
chloride. 


The  gas  grenades  held  0.446  pound  of  stannic  chloride, 
and  the  smoke  grenades  held  0.67  pound  of  white  phosphorus. 

The  only  type  of  shell  filled  was  the  75  mm.  variety,  because 
either  the  shell  of  the  other  sizes  or  the  accompanying  boosters 
(bursting  charges)  were  not  available. 

The  work  done  by  the  filling  plant  is  shown  by  the  follow- 
ing figures,  representing  the  number  of  shell,  grenades,  etc. 


75  mm.  Shell 

Filled 

Shipped 
Overseas 

Phosgene 

2,009 
427,771 
155,025 

N.C 

300,000 
150,000 

Mustard  gas 

Livens  Drum 

Phosgene 

25,689 

18,600 

^^m-  DEVI 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE        59 
Grenades 


White  phosphorus 
Tin  tetrachloride . 


440,153 
363,776 


224,984 
175,080 


Incendiary  Drop  Bomb 

Mark    I                        .                                   .... 

542 
2,104 

Mark  II 

The  total  monthly  capacity  of  the  filling  plants  at  the  date 
of  the  Armistice  was  as  follows : 

Pounds 

75  mm.  shell 2,400,000 

4.7  inch  shell 450,000 

155  mm.  shell 540,000 

6  inch  shell 180,000 

Gas  grenade 750,000 

Smoke  grenade 480,000 

Livens  drum 30,000 

One  point  relating  to  the  casualties  resulting  from  the 
work  should  perhaps  be  mentioned  here.  The  number  of 
casualties  should  change  the  mind  of  anyone  who  feels  that 
men  chose  this  work  as  being  "safe^'  instead  of  going  to 
France.  During  the  six  months  from  June  to  December  there 
were  925  casualties,  of  which  three  were  fatal,  two  being  due 
to  phosgene  and  one  to  mustard  gas.  These  were  divided 
among  the  different  gases  as  follows: 

Mustard  gas 674 

Stannic  chloride 50 

Phosgene 50 

Chloropicrin 44 

Chlorine 62 

Other  material 45 

Of  these  279  occurred  during  August,  197  during  September 
and  293  during  October.  Since  production  stopped  early  in 
November,  there  were  only  14  during  that  month  and  three 
during  December. 


60  CHEMICAL  WARFARE 

The  Staff  at  Edgewood  Arsenal  at  the  signing  of  the 
Armistice  was  as  follows : 

Commanding  Officer Colonel  Wm.  H.  Walker 

(Lt.  Colonel  George  Cahoon,  Jr. 
Lt.  Col.  Edward  M.  Ellicott 
Lt.  Col.  Wm.  C.  Gallowhur 
{Lt.  Col.  Wm.  McPherson 
Major  Adrian  Nagelvoort 
Major  Charles  R.  Wraith 
Captain  John  D.  Rue 

Shell  Filling  Plant Lt.  Col.  Edwin  M.  Chance 

Chlorine  Plant Lt.  Col.  Charles  Vaughn 

Chemical  Plants Major  Dana  J.  Demorest 

Chemical  Laboratory Major  William  L.  Evans 

As  the  work  of  the  Arsenal  expanded  it  was  necessary  to 
manufacture  certain  of  the  chemicals  at  outside  plants.  The  men 
in  charge  of  these  plants  were : 

Bound  Brook,  N.J Lt.  WiUiam  R.  Chappell 

Stamford,  Conn Lt.  V.  E.  Fishburn 

Hastings-on-Hudson,  N.  Y.  . .  .  Major  F.  G.  Zinnsser 

Niagara  Falls,  N.  Y Major  A.  Nagelvoort 

Buffalo,  N.  Y Lt.  A.  W.  Davison 

Kingsport,  Tenn Lt.  E.  M.  Hayden 

Charleston,  W.  Va Lt.  M.  R.  Hoyt 

Midland,  Mich Major  M.  G.  Donk 

Croyland,  Pa Capt.  A.  S.  Hulburt 

After  the  Armistice,  Edgewood  Arsenal  was  selected  as  the 
logical  home  of  the  Chemical  Warfare  Service,  and  all  the  outside 
activities  of  the  Service  were  gradually  closed  up  and  the  physical 
property  and  files  moved  to  Edgewood.  At  first  the  command  of 
the  Arsenal  was  in  the  hands  of  Lt.  Col.  Fries,  but  when  he  was 
appointed  Chief  of  the  Service,  Major  E.  J.  Atkisson,  who  had  so 
successfully  commanded  the  First  Gas  Regiment,  A.  E.  F.,  was 
happily  chosen  his  successor.  At  the  present  time  (July  1, 1921), 
the  organization  of  Edgewood  Arsenal  is  as  follows : 

Commandmg  Officer Major  E.  J.  Atkisson 

Executive  Officer Major  R.  C.  Ditto 

Technical  Director Dr.  J.  E.  Mills 

Chemical  Division Mr.  D.  B.  Bradner 

Mechanical  Division Mr.  S.  P.  Johnson 

Plant  Division Capt.  E.  G.  Thompson 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE        61 

Chemical  Warfare  School Major  O.  R.  Meredith 

Property Major  A.  M.  Heritage 

First  Gas  Regiment Major  C.  W.  Mason 

Mask  Production  Division Lt.  L.  A.  Elliott 

Medical  Department Major  T.  L.  Gore 

Pathological  Division Lt.  H.  A.  Kuhn 

Quartermaster  Department..  . .  Capt.  H.  L.  Hudson 

Finance  Department Capt.  C.  R.  Insley 

Development  Division 

The  Development  Division  had  its  origin  in  the  research 
laboratories  of  the  National  Carbon  Company  and  of  the 
National  Lamp  Works  of  the  General  Electric  Company.  Both 
of  these  companies  knew  charcoal,  and  they  were  asked  to 
produce  a  satisfactory  absorbent  charcoal.  The  success  of 
this  undertaking  will  be  seen  in  the  charter  on  Absorbents. 
After  a  short  time  all  the  laboratory  work  was  taken  over 
by  the  National  Carbon  Co.,  while  the  developmental  work 
was  assigned  to  the  National  Lamp  Works.  When  the  final 
organization  of  the  Chemical  Warfare  Service  took  place,  the 
National  Carbon  Laboratory  became  part  of  the  Research 
Division,  while  the  National  Lamp  Works  became  the  Defense 
Section  of  the  Development  Division. 

The  Development  Division  may  be  considered  as  having 
bee  1  composed  of  the  following  sections : 

1.  Defense 

2.  Offense 

3.  Midland 

4.  Willoughby 

5.  Special  Investigation. 

The  work  of  the  Defense  Section  consisted  of  the  develop- 
ment of  a  charcoal  suitable  for  use  in  gas  masks,  and  its  manu- 
facture. While  the  details  will  be  given  later,  it  may  be  men- 
tioned here  that  three  weeks  after  the  organization  of  the 
Section  (April  28,  1917)  the  furnaces  of  the  National  Carbon 
Company  were  turning  out  cedar  charcoal,  using  a  straight 
distillation  procedure.  Cedar  was  selected  from  a  large  variety 
of  materials  as  giving  the  highest  absorptive  value  against 
chlorine.    But  phosgene  and  chloropicrin  were  also  being  used, 


62  CHEMICAL  WARFARE 

and  it  was  found  that  the  cedar  charcoal  was  not  effective 
against  either.  Proceeding  on  a  definite  hypothesis,  fifty 
materials  were  investigated  to  find  the  charcoal  with  the 
highest  density.  Cocoanut  hulls  furnished  the  raw  material, 
which  yielded  the  most  active  charcoal.  By  a  process  of  air 
activation  a  charcoal  was  obtained  which  possessed  high  absorp- 
tive power  for  such  gases  as  chloropicrin  and  phosgene.  Later 
this  air  process  was  changed  to  one  in  which  steam  is  used; 
the  cocoanut  shell  charcoal  activated  with  steam  was  given 
the  name  "Dorsite." 

Complete  apparatus  for  this  air  process  was  installed  at  the 
plant  of  the  Astoria  Light,  Heat  &  Power  Company,  Long  Island 
City,  and  the  first  charcoal  was  prepared  during  September, 
1917.  This  was  followed  by  a  large  amount  of  experimental 
work,  relating  to  the  raw  material,  the  method  of  activation, 
and  the  type  of  furnace  used.  Because  of  the  shortage  of 
cocoanut  hulls,  it  later  became  necessary  to  use  a  mixture  of 
cocoanuts  with  cohune  nuts,  apricot  and  peach  pits,  cherry 
pits  and  vegetable  ivory.  Another  substitute  for  cocoanut 
charcoal  was  found  in  a  steam  activated  product  from  high 
grade  anthracite  coal,  called  **Batchite.*' 

The  Offense  Section  and  the  Midland  Section  were  con- 
cerned with  the  manufacture  of  mustard  gas.  This  work  was 
greatly  delayed  because  of  the  unsatisfactory  nature  of  the 
so-called  chlorohydrin  process.  Another  difficulty  was  the 
development  of  a  satisfactory  ethylene  furnace.  Finally  in 
February,  1918,  Pope  in  England  discovered  the  sulfur  chloride 
method  of  making  mustard  gas.  At  once  all  the  energies  of 
the  Research  Division  were  concentrated  on  this  process,  and 
in  March  steps  were  taken  to  put  this  process  into  production. 
An  experimental  plant  was  established  at  Cleveland;  no 
attempt  was  made  to  manufacture  mustard  gas  on  a  large 
scale,  but  the  results  obtained  in  the  experimental  studies  were 
immediately  transmitted  to  the  manufacturing  plants  at  Edge- 
wood  Arsenal,  the  Hastings-on-Hudson  plant,  the  National 
Aniline  &  Chemical  Company  (Buffalo)  plant,  and  the  Dow 
Chemical  Company  (Midland)  plant.  The  details  of  the  work  on 
mustard  gas  will  be  given  in  a  later  chapter. 

Special  investigations  were  undertaken  to  develop  a  booster 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE        63 

casing  and  adapter  for  75  mm.  gas  shell,  and  to  duplicate  the 
French  process  of  lining  gas  shell  with  glass. 

The  organization  of  the  Development  Division  at  the  signing 
of  the  Armistice  was  as  follows : 

Colonel  F.  M.  Dorsey Chief  of  the  Division 

Major  L.  J.  Willien Supt.,  Offense  Section 

Capt.  O.  L.  Barnebey Supt.,  Defense  Section 

Lt.  Col.  W.  G.  Wilcox Supt.,  Experimental  Station 

Capt.  Duncan  MacRae Special  Investigation  Section 

Dr.  A.  W.  Smith Midland  Section 

Capt.  J.  R.  Duff Administrative  Section 

Proving  Division 

The  Proving  Division  had  its  origin  in  the  decision  to  build  an 
Experimental  Ground  for  gas  warfare  under  the  direction  of  the 
Trench  Warfare  Section  of  the  Ordnance  Department.  While 
this  decision  was  reached  about  September,  1917,  actual  work  on 
the  final  location  (Lakehurst,  N.  J.)  was  not  started  until  March 
26,  1918,  and  the  construction  work  was  not  completed  until 
August  1,  1918.  However,  firing  trials  were  started  on  April  25, 
1918,  and  in  all  82  were  carried  out. 

The  Proving  Division  was  created  to  do  two  things:  To 
experiment  with  gas  shell  before  they  reached  the  point  where 
they  could  be  manufactured  safely  in  large  numbers  for  ship- 
ment overseas ;  and  to  prove  gas  shell,  presumably  perfect  and 
ready  for  shipment,  to  guard  against  any  mechanical  inaccura- 
cies in  manufacture  or  filling.  It  is  evident  that  the  second 
proposition  is  dependent  upon  the  first.  Shell  can  not  be 
proved  to  ascertain  the  effect  of  gases  under  various  conditions 
and  concentrations  until  the  mechanical  details  of  the  shell 
itself,  purely  an  Ordnance  matter,  have  been  standardized. 
Unfortunately  many  of  the  tests  carried  out  had  to  do  with  this 
very  question  of  testing  Ordnance. 

For  field  concentration  work  two  complete  and  separate 
lines  of  trenches  were  used  and  also  several  impact  grounds. 
The  trenches  were  built  to  simulate  the  trenches  actually  used 
in  warfare.  Each  line  of  trench  contained  several  concrete 
shell-proof  dugouts  and  was  also  equipped  with  shelves  into 
which  boxes  could  be  placed  for  holding  the  sample  bottles. 


64  CHEMICAL  WARFARE 

At  intervals  of  one  yard  throughout  the  trenches  there  were 
electrical  connections  available  for  electrical  sampling  purposes. 
The  various  impact  grounds  were  used  for  cloud  gas  attacks, 
and  experiments  with  mustard  gas  or  in  many  cases  for  static 
trials.  The  samples  were  collected  by  means  of  an  automatic 
sampling  apparatus. 

The  work  of  the  Division  consisted  in  the  first  instance  of 
determining  the  proper  bursting  charge.  While  a  great  deal 
of  this  work  had  been  carried  out  in  Europe,  American  gas 
shell  were  enough  different  to  require  that  tests  be  carried 
out  on  them.  The  importance  of  this  work  is  obvious,  since 
phosgene,  a  substance  with  a  low  boiling  point,  would  require 
a  smaller  bursting  charge  to  open  the  shell  and  allow  the 
substance  to  vaporize  than  would  mustard  gas,  where  the 
bursting  charge  must  be  not  only  sufficient  to  fragment  the 
shell  but  also  to  scatter  the  liquid  so  that  it  would  be  atomized 
over  the  largest  possible  area.  In  the  case  of  low  boiling 
liquids  it  was  necessary  that  the  charge  be  worked  out  very 
carefully  as  a  difference  of  one  or  two  grams  would  seriously 
affect  the  concentration.  Too  small  a  charge  would  allow  a 
cup  to  be  formed  by  the  base  of  the  shell  which  would  carry 
some  of  the  liquid  into  the  ground,  while  too  great  an  amount 
of  explosive  tended  to  throw  the  gas  too  high  into  the  air. 

After  the  bursting  charge  had  been  determined  a  large 
number  of  shell  were  repeatedly  fired  into  the  trenches,  wooded 
areas,  rolling  and  level  ground,  and  the  concentration  of  gas 
produced  and  the  effect  upon  animals  placed  tvithin  the  area 
ascertained.  From  the  results  of  these  experiments  the  Proving 
Division  was  able  to  furnish  the  artillery  with  data  regarding 
how  many  shell  of  given  caliber  should  be  used,  with  correc- 
tions for  ranges,  wind  velocities,  temperatures,  ground  condi- 
tions, etc.  Trials  were  also  held  to  determine  how  many 
high  explosive  (H.E.)  shell  could  be  fired  with  gas  shell  on 
the  same  area  without  unduly  affecting  the  concentration. 
This  was  important,  because  H.E.  shell  were  useful  in  dis- 
guising gas  bombardments.  Gas  shell  can  usually  be  dis- 
tinguished by  the  small  detonation  on  bursting. 

Experiments  were  performed  to  determine  the  decomposi- 
tion of  various  gases  on  detonation.    The  shell  were  fired  at  a 


I 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE        65 


large  wooden  screen  and  burst  on  impact.  Samples  of  gas  were 
taken  immediately  and  analyzed. 

Co-operative  tests  were  carried  out  with  the  Gas  Defense 
Division  to  determine  the  value  of  given  masks  under  field 
conditions.  Companies  of  infantry,  fully  equipped  for  the  field, 
would  wear  masks  for  hours  at  a  time  digging  trenches,  cutting 
timber,  drilling,  etc.,  and  imitating  in  every  way,  as  far  as 
possible,  actual  field  conditions.  During  these  activities  tons 
of  gas  in  cylinders  were  released  in  such  a  way  that  the  men 
were  enveloped  in  a  far  higher  concentration  than  would  prob- 
ably ever  be  the  case  in  actual  battle.  These  tests  gave  valu- 
able data  for  criticizing  gas  mask  construction. 

Another  line  of  activity  consisted  of  a  study  of  the  persistency 
and  relative  effectiveness  of  various  samples  of  mustard  gas, 
in  which  the  liquid  was  distributed  uniformly  upon  the  surface 
of  grassy  zones  one  to  three  feet  in  width,  which  formed  the 
periphery  of  circular  areas  14  to  21  feet  in  diameter,  the 
central  part  of  each  circle  being  occupied  by  animals. 

The  work  of  the  Proving  Division  was  brought  to  an  end 
(by  the  Armistice)  just  at  the  time  when  it  had  reached  its 
greatest  usefulness.  Not  only  were  the  physical  properties 
and  personnel  of  the  Division  developed  to  the  maximum 
degree,  but  the  production  of  gas  shell  in  this  country  for 
shipment  to  France  had  just  reached  the  stage  where  the 
Proving  Ground  could  have  been  used  to  its  fullest  extent  in 
their  proving. 

Training  Division 

From  the  standpoint  of  the  man  at  the  front  the  Training 
Division  is  one  of  the  most  important.  To  him  gas  warfare  is  an 
ever  present  titanic  struggle  between  poisonous  vapors  that  kill 
on  one  side,  and  the  gas  mask  and  a  knowledge  of  how  and  when 
to  wear  it,  on  the  other.  Because  of  this  it  is  rather  surprising 
that  we  did  not  hear  more  about  this  branch  of  the  Service.  It 
did  exist,  however,  and  credit  must  be  given  to  those  camp  gas 
officers  who  remained  in  the  United  States  performing  an  incon- 
spicuous and  arduous  duty  in  the  face  of  many  local  obstacles. 

The  Field  Training  Division  of  the  Gas  Defense  Service 
in  the  United  States  was  organized  in  September,  1917,  and 


66 


CHEMICAL  WARFARE 


consisted  of  Major  J.  H.  Walton  and  45  first  lieutenants,  all 
chemists.  These  men  were  given  a  three  months'  military 
training  at  the  American  University.  The  arrival  of  Major 
(now  Colonel)  Auld  during  this  time  was  very  helpful,  as  he 
was  able  to  give  the  Section  first-hand  knowledge.  About  12 
of  the   45   men  were   sent   to  France,   while   the   remainder. 


DIVISIONAL   GAS  OFFICER 


•i^ 


i^. 


^4^. 


1    -   TRgNCM    TAX 

i— TEST     BOTTLES 

J  —  &A4    ouovta 

?' 

<       i»*oTtcrnrt  t.'M  »ooT,s 

^ 

J_OVt«A.l.l.      PROT-EtTIVf     J.'J'-r 

^  -  HCRie   • MAin 

-J    -     »<.l.*>XON 

6  -  r^uHt  riTj 

3    -     BLf  At  M!N«r       POV*DCR 

^ 

,0-     I-ILINV     CABlX.tr      TORtMAmrl 

YOU    MAOt     ME    WHAT     i    AM     TO-OAY 


I  HOPE    YOURE    3ATlsnco 


Fig.  8. 

together  with  British  Gas  Officers,  were  assigned  to  various 
Divisions  still  in  training.  There  was  little  idea  at  that  time 
as  to  what  constituted  real  gas  training.  No  one  knew  how 
much  gas  training  would  be  received  in  France,  and  since  little 
w.as  often  received  due  to  lack  of  time,  many  men  went  into 
action  with  no  idea  of  what  this  training  really  meant.  More- 
over, an  order  that  the  gas  officers  should  not  go  to  France 


DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE        67 

with  their  Divisions  had,  as  was  only  natural,  a  discouraging 
effect  upon  the  men  and  upon   gas  training  and  discipline 

generally. 

In  January,  1918,  the  gas  officers  were  transferred  to  the 
Engineers,  and  designated  as  the  473d  Engineers.  Later  an 
Army  Gas  School  was  established  at  Camp  Humphreys.  Because 
of  the  rapidly  changing  personnel,  owing  to  overseas  assign- 
ments, the  policy  was  adopted  of  sending  specialized  gas  officers 
only  to  Divisional  Camps  and  the  larger  training  centers.  The 
need  of  xi  larger  unit  and  increased  authority  was  recognized 
by  all  intimately  associated  with  the  work,  but  little  was 
accomplished  until  the  transfer  to  the  Chemical  Warfare 
Service.  Upon  the  appointment  of  Brigadier  General  H.  C. 
Newcomer  as  Assistant  Director  of  the  Chemical  Warfare 
Service,  he  was  placed  in  charge  of  all  military  affairs  of  the 
Service,  and  the  administrative  officers  of  the  Training  Section 
became  his  "military  assistants."  A  few  weeks  later  the  Train- 
ing Section  of  the  Administration  Division,  C.W.S.  was  formed. 

At  this  time  new  duties  fell  to  the  lot  of  this  Section,  among 
the  more  important  being: 

(1)  The  organization  of  gas  troops' and  casual  detachments 
for  overseas  duty; 

(2)  The  establishment  of  a  Chemical  Warfare  Training 
Camp ; 

(3)  The  procurement  and  training  of  officers  for  overseas 
duty. 

For  this  purpose  a  training  camp  was  established  near  the 
Proving  Ground  (Camp  Kendrick)  to  hold  1300  officers  and 
men.  Line  officers  were  sent  from  the  larger  camps  for  train- 
ing, the  best  of  whom  might  later  be  transferred  to  the  Chemical 
Warfare  Service  for  duty  as  Gas  Officers. 

The  work  of  the  Section  eventually  grew  to  such  propor- 
tions that  it  was  recognized  as  the  Training  Division  of  the 
Chemical  Warfare  Service.  It  differed  from  other  Divisions 
in  that  all  administrative  routine  was  carried  on  through  the 
offices  of  the  Director,  and  with  the  assistance  and  co-operation 
of  its  various  Sections. 

Because  of  the  formation  of  the  Chemical  Warfare  Service 
and  the  apparent  need  for  officers,  the  office  was  soon  flooded 


68  CHEMICAL  WARFARE 

with  applications  for  commissions.  These  were  carefully 
examined  and  the  men  were  sent  first,  by  courtesy  of  the  Chief 
of  Engineers,  to  Camp  Humphreys  for  a  month's  course  of 
military  training.  At  the  end  of  this  period  they  were  sent 
to  Camp  Kendrick  as  students  of  the  Army  Gas  School.  Toward 
the  last  of  October  all  the  officers  and  enlisted  men  were  trans- 
ferred to  Camp  Kendrick  where  an  Officers '  Training  Battalion 
was  organized. 

It  is  obvious  that  the  gas  training  of  troops  was  the  most 
responsible  duty  of  the  Training  Division.  There  was  con- 
stantly in  mind  an  ideal  of  supervised  and  standardized  train- 
ing for  all  troops  in  the  United  States,  and  the  Division,  at 
the  time  of  the  Armistice,  for  the  first  time  found  itself  with 
a  nearly  adequate  corps  of  officers  through  whom  this  ideal 
could  be  realized. 

Medical  Division 

Dr.  Yandell  Henderson  of  Yale  University  was  the  logical 
man  to  inaugurate  the  medical  work  of  the  Bureau  of 
Mines,  because  of  his  experience  with  oxygen  rescue 
apparatus.  A  member  of  the  first  committee  of  the  Bureau, 
he  secured,  in  July,  1917,  an  appropriation  for  the  study 
of  toxic  gases  at  Yale.  This  was  in  charge  of  Doctors 
Underbill,  therapy;  Marshall,  pharmacology;  and  Winternitz, 
pathology.  When  the  American  University  Station  was  opened 
Marshall  was  given  charge  of  the  pharmacology.  About  the 
same  time  a  factory  protection  unit  was  organized  under  the 
direction  of  Doctors  Bradley,  Eyster  and  Loevenhart.  At  first 
this  committee  reported  to  the  Ordnance  Department,  but  later 
the  work  was  transferred  to  the  Gas  Defense  Service. 

In  December,  1917,  the  Medical  Advisory  Board  was 
organized.  This  included  all  the  men  who  were  carrying  on 
experimental  work  of  a  medical  nature.  This  board  had  as 
its  object  the  correlation  of  all  medical  work;  new  work  was 
outlined  and  attempts  were  made  to  secure  the  co-operation 
of  scientific  men  throughout  the  country.  The  following  groups 
of  workers  assisted  in  this  effort:  At  Yale,  Underbill  studied 
therapy,  turning  his  animals  over  to  Winternitz  for  pathological 


•  DEVELOPMENT  OF  CHEMICAL  WARFARE  SERVICE        69 

study.  Henderson  was  specially  interested  in  the  physiology 
of  aviation.  At  the  American  University  Marshall  carried 
on  pharmacological  research,  specially  as  regards  mustard  gas, 
the  toxicology  being  covered  by  Loevenhart.  A  pathological 
laboratory  was  also  started,  under  Winternitz,  where  many 
valuable  studies  were  made.^  At  Cleveland  Sollmann  was 
busy  with  mustard  gas  and  protective  agents.  Pearce,  work- 
ing in  co-operation  with  Dr.  Geer  of  the  Goodrich  Rubber 
Company,  perfected  the  Goodrich  Lakeside  Mask.  His  study 
was  very  valuable  as  concerning  the  physiology  of  the  gas 
mask.  At  Ann  Arbor  Warthin  and  Weller^  were  studying  the 
physiology  and  pathology  of  mustard  gas.  Wells,  Amberg, 
Helmholz  and  Austin  of  the  Otho  Sprague  Memorial  Institute 
were  interested  in  protective  clothing,  while  at  Madison, 
Eyster,  Loevenhart  and  Meek  were  engaged  in  a  study  of  the 
chronic  effect  of  long  exposures  to  low  concentrations,  and 
later  expanded  their  work  to  protective  ointments  and  certain 
problems  in  pathology. 

Li  the  spring  of  1918  many  of  these  men  were  commis- 
sioned into  the  Gas  Defense  Service  of  the  Sanitary  Corps, 
and  were  later  transferred  to  the  Chemical  Warfare  Service 
as  the  Medical  Division,  with  Colonel  W.  J.  Lyster,  M.C.,  in 
charge. 

One  of  the  most  important  functions  of  this  Division  was 
the  daily  testing  of  a  large  number  of  compounds  for  toxicity, 
lachrymatory  or  vesicant  properties.  The  accuracy  of  these 
tests  might  and  probably  did  save  a  large  amount  of  unneces- 
sary experimental  work  on  the  part  of  the  Research  Division. 
These  tests  are  described  in  a  later  chapter. 

Very  interesting  and  likewise  valuable  was  the  study  of 
mustard  gas  by  Marshall,  Lynch  and  Smith.  They  were  able 
to  work  out  the  mechanism  of  its  action  and  the  varying 
degrees  of  susceptibility  in  individuals  (see  page  171). 

Another  interesting  point  was  the  fact  that  in  the  case 
of  certain  gases  there  is  a  cumulative  effect.  With  superpalite 
and  mustard  gas  the  lethal  concentration  (that  concentration 
which  is  fatal  after  a   given   exposure)    is  lower  on  longer 

*  See  the  Pathology  of  War  Gas  Poisoning,  1920,  Yale  Press. 

-  See  Medical  Aspects  of  Mustard  Gas  Poisoning,  1919,  C.  O.  Mosby  Co. 


70  CHEMICAL  WARFARE 

exposures.  On  the  other  hand  there  is  no  cumulative  effect 
with  hydrocyanic  acid.  Whether  the  action  is  cumulative  or 
not  depends  on  the  rate  at  which  the  system  destroys  or 
eliminates  the  poison. 

Liaison  Officers 

This  chapter  should  not  be  closed  without  reference  to  the 
Liaison  Service  that  was  established  between  the  United  States 
and  her  Allies,  especially  England. 

During  the  early  days  no  one  in  the  States  was  familiar 
with  the  details  of  gas  warfare.  At  the  request  of  the  Medical 
Corps,  upon  the  urgent  representations  of  the  Gas  Service, 
A.E.F.,  Captain  (now  Major)  H.  W.  Dudley  was  sent  to  this 
country  (Sept.,  1917)  to  assist  in  the  development  and  manu- 
facture of  gas  masks.  For  some  time  he  was  the  Court  of 
Appeal  on  nearly  all  technical  points  regarding  matters  of 
defense.  Dudley's  continual  insistence  on  the  need  for  main- 
taining the  highest  possible  standard  of  factory  inspection  was 
one  of  the  factors  resulting  in  the  excellent  construction  of 
the  American  Mask.  In  March,  1918,  Lieut.  Col.  Dewey  and 
Captain  Dudley  made  a  trip  to  England  and  France,  during 
which  the  idea  of  a  liaison  between  the  defense  organizations 
of  the  two  countries  originated.  Dudley  was  transferred  to 
the  Engineers,  promoted  and  placed  in  charge  of  the  Liaison 
service.  While  the  time  until  the  Armistice  was  too  short  to 
really  test  the  idea,  enough  was  accomplished  to  show  the 
extreme  desirability  of  some  such  arrangement. 

Probably  the  best  known  liaison  officer  from  the  British 
was  Colonel  S.  J.  M.  Auld,  also  sent  upon  the  urgent  represen- 
tations of  the  Gas  Service,  A.E.F.  He  arrived  in  this  country 
about  the  middle  of  October,  1917,  in  charge  of  28  officers  and 
28  noncommissioned  officers,  who  were  to  act  as  advisers  in 
training  and  many  other  military  subjects  besides  gas  warfare. 
Since  Auld  had  had  personal  experience  with  gas  warfare  as 
then  practiced  at  the  front,  his  advice  was  welcomed  most 
heartily  by  all  the  different  branches  of  the  Army  then 
handling  gas  warfare.  On  questions  of  general  policy  Auld 
was  practically  the  sole  foreign  adviser.     The  matter  of  gas 


I 


DEVELOPMENT  OF  CHEMICAL  SERVICE  WARFARE        71 


training  was  transferred  from  the  Medical  Corps  to  the 
P^ngineers,  and  was  greatly  assisted  by  four  pamphlets  on  Gas 
Warfare  issued  by  the  War  College,  which  were  prepared  by 
Major  Auld  with  the  assistance  of  Captain  Walton  and  Lieut. 
Bohnson.  Later  Auld  gave  the  American  public  a  very  clear 
idea  of  gas  warfare  in  his  series  of  articles  appearing  in 
the  Saturday  Evening  Post,  and  re-written  as  ''Gas  and 
Flame." 

Major  H.  R.  LeSueur,  who  was  at  Porton  previous  to  his 
arrival  in  this  country  in  December,  1917,  rendered  valuable 
aid  in  establishing  the  Experimental  Proving  Ground  and  in 
its  later  operations. 

Towards  the  close  of  the  war  the  British  War  Office  had 
di-awn  up  a  scheme  for  a  Gas  Mission,  which  was  to  correlate 
all  the  gas  activities  of  England  and  America.  This  was  never 
carried  through  because  of  the  signing  of  the  Armistice. 

The  French  representatives,  M.  Grignard,  Capt.  Ilankar 
and  Lt.  Engel  furnished  valuable  information  as  to  French 
methods,  but  they  were  handicapped  by  the  fact  that  French 
manufacturers  did  not  disclose  their  trade  secrets  even  to  their 
own  Government. 

About  August,  1918,  Lieut.  Col.  James  F.  Norris  opened  an 
office  in  London.  His  duties  were  to  establish  cordial  and 
intimate  relations  not  only  with  the  various  agencies  of  the 
British  Government  which  were  connected  with  gas  warfare, 
but  also  with  the  various  laboratories  where  experiments  were 
l)eing  conducted,  that  important  changes  might  be  transmitted 
to  America  with  the  least  possible  delay.  The  English  made 
Colonel  Norris  a  member  of  the  British  Chemical  Warfare 
Committer.  Here  again  the  signing  of  the  Armistice  prevented 
a  full  realization  of  the  importance  of  this  work. 


CHAPTER   IV 
THE   CHEMICAL  WARFARE  SERVICE  IN  FRANCE 

It  is  worth  noting  here  that  the  Chemical  Warfare  Service 
was  organized  as  a  separate  service  in  the  American  Expedi- 
tionary Forces  nearly  ten  months  before  it  was  organized  in 
the  United  States,  and  that  the  organization  in  the  United 
States  as  heretofore  described  was  patterned  closely  on  that 
found  so  successful  in  France. 

Very  soon  after  the  United  States  declared  war  against  the 
Central  Powers,  a  commission  was  sent  abroad  to  study  the 
various  phases  of  warfare  as  carried  on  by  the  Allies,  and  as 
far  as  possible  by  the  enemy.  Certain  members  of  this  com- 
mission gave  attention  to  chemical  warfare.  One  of  those  who 
did  this  was  Professor  Hulett  of  Princeton  University.  He, 
with  certain  General  Staff  officers,  gathered  what  information 
they  could  in  England  and  France  concerning  the  gases  used 
and  methods  of  manufacturing  them,  and  to  a  very  slight 
extent  the  methods  of  projecting  those  gases  upon  the  enemy. 
Some  attention  was  paid  to  gas  masks,  but  there  being  nobody 
on  the  General  Staff,  or  anywhere  else  in  the  Regular  Army, 
whose  duty  it  was  to  look  out  particularly  for  chemical  war- 
fare materials,  these  studies  produced  no  results. 

As  has  already  been  stated,  the  Medical  Department  started 
the  manufacture  of  masks,  and  the  Bureau  of  Mines,  under 
the  leadership  of  the  Director,  Mr.  Manning,  began  studies 
upon  poisonous  gases  and  the  methods  of  manufacturing  them 
just  before  or  shortly  after  war  was  declared. 

Nevertheless,  although  American  troops  left  for  France  in 
May,  1917,  it  was  not  until  the  end  of  August — the  17th 
to  be  exact — that  definite  action  was  taken  toward  establishing 
a  Chemical  Warfare  Service,  or,  as  it  was  then  known,  a  Gas 

72 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE  73 

Service  in  the  American  Expeditionary  Forces.  On  that  date 
a  cablegram  was  sent  to  the  United  States  to  the  effect  that 
it  was  desired  to  make  Lieut.  Col.  Amos  A.  Fries,  Corps  of 
P^ngineers,  Chief  of  the  Gas  Service,  and  requesting  that  no 
assignments  to  the  regiment  of  gas  troops  authorized  in  the 
United  States  be  made  which  would  conflict  with  this  appoint- 
ment. On  August  22d,  Lieut.  Col.  Fries  entered  upon  his  duties 
as  Chief  of^the  Gas  Service. 

There  were  then  in  France  about  30  miles  from  the  German 
lines,  some  12,000  American  troops  without  any  gas  masks  or 
training  whatever  in  Chemical  Warfare.  Immediate  steps  were 
taken  to  teach  the  wearing  of  the  masks,  and  English  and 
French  gas  masks  were  obtained  for  them  at  the  earliest  pos- 
sible moment.  At  the  same  time  efforts  were  made  to  obtain 
officer  personnel  for  the  C.  W.  S.,  and  to  have  sent  to  France 
a  laboratory  for  making  such  emergency  researches,  experi- 
ments, and  testing  as  might  become  necessary.  From  that  time 
to  the  end  of  the  war  the  C.  W.  S.  continued  to  develop  on 
broad  lines  covering  research,  development,  and  manufacture ; 
the  filling  of  shell  and  other  containers  with  poisonous  gases, 
smoke  and  incendiary  materials;  the  purchase  of  gas  masks 
and  other  protective  devices,  as  well  as  the  handling  and 
supply  of  these  materials  in  the  field;  the  training  of  the 
Army  in  chemical  warfare  methods,  both  in  offense  and 
defense;  and  the  organization,  equipment  and  operation  of 
special  gas  troops. 

This  gave  an  ideal  organization  whereby  research  was 
linked  with  the  closest  possible  ties  to  the  firing  line,  and  where 
the  neeessities  of  the  firing  line  were  brought  home  to  the 
supply  and  manufacturing  branches  and  to  the  development 
and  research  elements  of  the  Service  instantly  and  with  a 
force  that  could  not  have  been  obtained  in  any  other  manner. 
The  success  of  the  C.  W.  S.  in  the  field  and  at  home  was  due 
to  this  complete  organization.  To  the  Commander-in-Chief, 
General  Pershing,  is  due  the  credit  for  authorizing  this  organ- 
ization and  for  backing  it  up  whenever  occasion  demanded. 
Other  details  of  this  work  will  be  considered  under  the  follow- 
ing heads:  Administrative;  Training;  Chemical  Warfare 
Troops ;  Supply ;  Technical ;  Intelligence ;  and  Medical. 


74  CHEMICAL  WARFARE 


Administrative  Duties  ^ 

The  duties  of  administration  covered  those  necessary  for 
a  general  control  of  research,  of  supply,  of  training,  and  the 
operation  of  special  gas  troops.  At  fir^t  the  Chief  of  the  Gas 
Service  comprised  the  whole  of  the  Service  since  he  was  with- 
out personnel,  material,  rules,  regulations,  or  anything  else 
of  a  chemical  warfare  nature. 

The  experience  in  getting  together  this  organization  should 
be  sufficient  to  insure  that  the  United  States  will  never  place 
on  any  other  man's  shoulders  tlie  burden  of  organizing  a  new 
and  powerful  service  in  the  midst  of  war,  4,000  miles  from 
home,  without  precedent,  material,  or  anything  else  on  which 
to  base  action.  It  is  true  the  Americans  had  available  the 
experience  of  the  English  and  the  French,  and  it  should  be 
said  to  the  credit  of  both  of  these  nations  that  they  gave  of 
their  experience,  their  time,  and  their  material  with  the  great- 
est freedom  and  willingness,  but  just  as  Americans  are  Ameri- 
cans and  were  Americans  in  1917,  just  so  the  methods  of  the 
French  and  English  or  of  the  enemy  were  not  entirely  suitable 
to  American  conditions. 

If  there  is  any  one  thing  needed  in  the  training  of  U.  S. 
Army  leaders  of  today  and  for  the  future,  it  is  vision — vision 
that  can  foresee  the  size  of  a  conflict  and  make  preparations 
accordingly.  We  do  not  mean  vision  that  will  order,  as  hap- 
pened in  some  cases,  ten  times  as  much  material  as  could 
possibly  be  used  by  even  5,000,000  troops,  but  the  sort  of  vision 
that  could  foresee  in  the  fall  of  1917  that  2,000,000  men  might 
be  needed  in  France  and  then  make  preparations  to  get 
materials  there  for  those  troops  by  the  time  they  arrived. 

In  order  to  cover  the  early  formative  period  of  the  C.  W.  S. 
in  France  and  to  shoAV  some  of  the  difficulties  encountered, 
the  following  running  account  is  given  of  some  of  the  early 
happenings  without  regard  to  the  sub-divisions  under  which 
they  might  properly  be  considered. 

Assignment  of  Chief  of  the  Gas  Service.  Sailing  from  the 
United  States  on  the  23d  of  July,  1917,  Fries  arrived  in  Paris 
on  the  morning  of  August   14,   1917,   and  was  immediately 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE  75 

assigned  the  task  of  organizing  a  highway  service  for  the 
American  Expeditionary  Forces.  Five  days  later  and  before 
the  highway  order  was  issued,  he  was  asked  what  he  would 
think  if  his  orders  were  changed  so  as  to  make  him  Chief 
of  the  newly  proposed  Gas  Service.  Being  given  one  night 
to  think  it  over  he  told  the  General  Staff  he  would  undertake 
the  work.  The  road  work  was  immediately  closed  up  and  on 
the  22d  of  August  the  organization  of  a  Gas  Service  was 
actively  started. 

At  that  time  some  information  concerning  gases  and  gas 
troops  had  been  gathered  by  Colonel  Barber  of  the  General 
Staff.  Likewise,  Colonel  (later  Brigadier  General)  Hugh  A. 
Drum  had  made  a  rough  draft  of  an  order  accompanied  by 
a  diagram  for  the  establishment  of  the  Gas  Service.  This 
information  was  turned  over  to  Fries  who  was  told  to  com- 
plete the  draft  of  tlie  order,  together  with  an  organization  chart, 
for  the  action  of  the  Commander-in-Chief.  After  one  and  a 
half  days  had  been  put  on  this  work  the  draft  and  chart  were 
considered  in  good  enough  shape  to  submit  to  General  Pershing, 
Commander-in-Chief. 

First  Trip  to  British  Gas  Headquarters.  Noting  that  the 
proposed  organization  provided  for  the  handling  of  4-inch 
Stokes'  mortars  by  gas  troops.  General  Pershing  asked  why 
this  work  Could  not  be  done  by  regular  trench  mortar  com- 
panies. He  was  told  that  gas  operations  were  too  technical 
and  dangerous  to  be  intrusted  to  any  but  especially  trained 
troops,  and  that,  furthermore,  it  was  understood  that  4-inch 
Stokes'  mortars  were  used  only  by  the  British  troops.  General 
Pershing  said,  "You  had  better  beat  it  to  the  British  Gas 
Headquarters  in  the  field  and  settle  definitely  that  and  certain 
other  minor  points."  Fries  told  him  he  was  only  too  glad 
to  do  this,  and,  having  completed  preparations,  left  on  the 
morning  of  August  25th  with  Colonel  Church  and  Captain 
Boothby,  both  of  the  Medical  Department,  for  St.  Omer,  Head- 
quarters of  the  British  Gas  Service  in  the  Field. 

Colonel  Church  of  the  Medical  Department  had  been  in 
France  nearly  one  and  a  half  years  prior  to  the  entry  of  the 
United  States  into  the  war,  and  had  taken  sufficient  interest 
in   Gas   AVarfare   to   collect   considerable   information   and  a 


76  CHEMICAL  WARFARE 

number  of  documents  from  French  sources  bearing  on  the 
defensive  side  of  the  subject.  Captain  Boothby  had  done  the 
same  with  the  British,  including  a  course  in  a  British  Gas 
Defense  School.  On  this  trip  they  took  up  the  defensive  side 
with  the  British,  while  Fries  took  up  the  offensive  side  of  the 
Service.  The  latter  included  gases  used,  gas  troops,  and  am- 
munition and  guns  used  in  Gas  Warfare  by  the  Artillery  and 
other  branches  of  the  Service.  The  trip  included  a  brief  visit 
to  the  headquarters  of  the  First  British  Army  in  the  vicinity 
of  Lens,  where  the  British  Gas  Service  had  a  large  depot  of 
offensive  gas  material. 

Order  Forming  Service.  Returning  on  the  28th  of  August 
the  order,  together  with  a  chart  organizing  the  Service,  was 
completed  and'  submitted  to  the  General  Staff.  This  was  pub- 
lished as  G.  0.  31,  September  3,  1917.  As  a  result  of  a  study 
of  the  information  submitted  by  Colonel  Barber  and  General 
Drum,  together  with  his  own  observations  of  British  organiza- 
tion and  work,  Fries  decided  it  was  advisable  to  make  the 
Service  cover  as  complete  a  scope  as  possible  and  to  make 
the  order  very  general,  leaving  details  to  be  worked  out  as 
time  and  experience  permitted.  This  proved  to  be  a  very  wise 
decision,  because  the  entire  absence  of  gas  knowledge  among 
Americans  either  in  France  or  the  United  States  made  it  neces- 
sary to  build  from  the  bottom  up  and  do  it  rapidly.  At  that 
time,  and  at  all  times  since,  it  was  found  utterly  impossible 
to  separate  the  defensive  side  from  the  offensive  side.  Indeed, 
many  of  the  worst  troubles  of  the  British  with  their  Gas  Service 
throughout  nearly  the  whole  war  arose  from  such  a  division 
of  duties  in  their  Service.  Thus,  the  development  of  masks 
must  be  kept  parallel  with  the  development  of  gases  and 
methods  of  discharging  them.  Otherwise  a  new  gas  invented 
may  penetrate  existing  masks  and  preparations  be  carried  far 
towards  using  it  before  the  development  of  masks  are  under- 
taken to  care  for  the  new  gas.  Obviously  a  gas  which  our  own 
masks  will  not  take  care  of  cannot  be  safely  used  by  our  own 
troops  until  new  masks  are  developed  to  protect  against  it. 

American  and  British  Masks.  Just  prior  to  Fries 's  assign- 
ment as  Chief  of  the  Gas  Service  twenty  thousand  American- 
made  masks  or  box  respirators  were  received  from  the  United 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE  77 

States.  Through  the  energy  of*  Captain  Boothby  several  of 
these  had  been  sent  at  once  to  the  British  for  test.  The  test 
showed  that  the  granules  in  the  canisters  were  entirely  too  soft, 
the  charcoal  of  poor  quality,  and  more  than  all  else,  the  fabric 
of  the  face  piece  was  so  pervious  to  gases  that  chloropicrin 
became  unbearable  to  the  eyes  in  less  than  a  minute  under 
the  standard  test  used  by  the  British.  A  cable  containing  this 
information  had  been  framed  and  sent  to  the  United  States 
just  prior  to  Fries 's  appointment  as  Chief  of  the  Service. 

August  23d,  the  day  after  Fries  took  charge,  it  was 
decided  to  adopt  the  British  mask  or  box  respirator  as  the 
principal  mask  and  the  French  M-2  as  an  emergency,  both 
to  be  carried  by  the  soldier,  the  French  M-2,  however,  to  be 
used  only  when  the  Britisli  mask  became  lost  or  unfit  for  use. 
A  requisition  for  one  hundred  thousand  of  each  was  at  once 
submitted  and  very  shortly  approved  by  the  General  Staff. 

Getting  Gas  Supplies.  It  should  be  stated  here  that  inas- 
much as  no  Gas  Service  had  been  organized  in  the  United 
States,  no  money  appropriation  had  been  made  for  it,  thereby 
making  it  necessary  for  the  Gas  Service  to  obtain  all  its  sup- 
plies through  other  departments  ordinarily  handling  the  same 
or  similar  materials.  Thus  defensive  supplies  were  obtained 
through  the  Medical  Department  and  offensive  supplies 
tlirough  the  Ordnance  Department,  while  other  miscellaneous 
equipment  was  obtained  through  the  Engineer  Department,  the 
Quartermaster  Department,  or  the  Signal  Corps.  This  pro- 
cedure proved  exceedingly  embarrassing,  cumbersome  and 
inefficient.  To  begin  with  it  was  necessary  to  get  some  agree- 
ment between  the  departments  as  to  what  each  would  supply. 
This  was  very  difficult,  resulting  in  delays  and  consumption  of 
time  which  was  urgently  needed  on  other  work. 

Not  only  was  there  trouble  in  getting  orders  accepted  and 
started  on  the  way  but  following  them  up  became  practically 
impossible.  None  of  the  Departments  furnishing  the  materials 
were  especially  interested  in  them  nor  in  many  instances  did 
they  realize  the  vital  nature  of  them.  Accordingly  in  order 
to  get  any  action  it  was  necessary  to  continually  follow  up 
all  orders  and  doing  this  through  another  department  created 
friction  and  misunderstanding.     Officers  of  these  departments 


78  CHEMICAL  WARFARE 

took  the  attitude  that  the  whole  question  of  obtaining  supplies 
should  be  left  to  them,  once  the  requistion  was  turned  in.  This 
could  not  be  done.  The  Chief  of  the  Gas  Service  was  absolutely 
responsible  for  gas  supplies,  and  he  fully  realized  that  no 
excuses  would  be  accepted,  no  matter  who  stood  in  the  way. 
It  was  necessary  to  get  action.  Finally  the  matter  was  settled, 
some  six  months  after  the  Service  was  organized,  by  giving 
the  Chemical  Warfare  Service  the  right  of  direct  purchase. 

Purchase  of  Offensive  Gas  Supplies.  Realizing  the  difficulty 
that  would  probably  be  encountered  in  getting  supplies  at  all 
times  from  the  British  and  French,,  two  requisitions  for  offen- 
sive gas  supplies  to  be  purchased  from  the  British  were  sub- 
mitted on  September  8th  and  10th  respectively.  It  would  seem 
proper  to  state  here  that  investigation  showed  the  British  gas 
organization  to  be  far  superior  to  the  French.  Indeed,  the 
latter  practically  had  no  organization. 

Consequently  it  was  determined  to  purchase  complete  equip- 
ment for  gas  troops  and  for  the  defensive  side  of  the  service 
from  the  British  and  to  make  no  attempt  to  produce  new 
materials,  methods  or  equipment  until  ample  supplies  of  the 
standard  equipment  of  the  British  were  at  hand  or  in  process 
of  manufacture  or  delivery.  This  was  another  exceedingly 
wise  conclusion.  No  supplies  of  any  kind  were  received  from 
the  United  States  for  the  next  eight  months,  and  then  only 
masks  and  certain  defensive  supplies.  Indeed,  no  cylinders, 
mortars,  projectors  or  artillery  shell  containing  gas  were 
received  from  the  United  States  until  just  before  the  Armistice, 
though  gas  had  been  available  in  the  United  States  for  months 
in  large  quantities,  over  3,600  tons  having  been  shipped  in  one- 
ton  containers  to  the  English  and  French.  The  Ordnance  material 
was  what  was  lacking. 

Obtaining  Personnel.  On  September  8,  Colonel  R.  W.  Craw- 
ford was  assigned  to  duty  with  the  Gas  Service.  This  matter 
of  obtaining  personnel  became  immediately,  and  continued  for 
almost  a  year  to  be,  one  of  the  most  serious  difficulties  facing 
the  new  Gas  Service.  The  troubles  here  again  were  the  same 
as  those  in  respect  to  supplies.  None  of  the  old  departments 
were  especially  interested  in  gas  and  hence  none  of  them 
desired  to  let  good  officers  be  transferred. 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE  79 

Officers  were  scarce  in  the  early  days  in  France  in  every 
department  of  the  Service,  consequently  a  new  department 
with  no  organization  in  the  United  States  and  no  precedents 
or  opportunities  for  promotion  made  the  obtaining  of  officers 
almost  a  matter  of  impossibility.  Further  than  this,  while  the 
Engineer  Department  was  at  first  supposed  to  furnish  most 
of  the  officer  personnel,  it  failed  to  do  so,  apparently  looking 
upon  the  Gas  Service  as  an  unimportant  matter  when  compared 
with  the  regular  work  of  the  Engineers.  It  was  necessary 
to  make  direct  application  to  the  Chief  of  Staff  to  obtain 
Colonel  Crawford  and  shortly  thereafter  to  cable  directly  to 
the  United  States  for  officers.  A  year  later  enough  officers 
were  obtained  but  only  after  the  organization  of  a  separate 
Service  in  the  United  States. 

Supplies  for  Gas  Troops.  Colonel  Crawford  was  at  once 
put  in  charge  of  all  supplies  for  the  Gas  Service,  including 
the  location  and  construction  of  separate  depots  for  that 
Service.  Prior  to  this  the  General  Staff  had  decided  to  have 
chemical  supplies  stored  in  depots  separate  from  those  of  other 
supplies  on  account  of  the  poisonous  nature  of  the  gases  which 
might  prove  very  annoying  if  leakage  occurred  near  any  other 
class  of  supplies.  Colonel  Crawford  took  hold  of  this  work 
with  zeal  and  energy  and  so  conducted  it  as  to  relieve  the 
Chief  of  the  Gas  Service  of  all  anxiety  in  that  matter.  As 
before  stated,  on  the  lOth  of  September  a  requisition  for  a 
very  large  quantity  of  offensive  supplies  for  gas  troops  was 
submitted  to  the  General  Staff  for  approval.  Inasmuch  as  this 
involved  approximately  50,000  gas  cylinders,  50,000  Liven 's 
drums,  with  at  least  20,000  Liven 's  projectors  and  a  large 
number  of  Stokes*  mortars  and  bombs,  there  was  considerable  dif- 
ficulty in  getting  it  approved.  Finally  Colonel  Malone  of  the 
Training  Section,  who  took  an  active  interest  in  the  Chemical 
Warfare  Service,  got  it  approved.  Then  began  the  difficulty  of 
getting  the  order  placed  and  of  trying  to  expedite  the  filling  of 
the  order  on  time.  These  difficulties  were  never  overcome  until 
after  the  entire  purchase  of  supplies  was,  as  previously  related, 
taken  care  of  by  the  Gas  Service. 

First  Inter-allied  Gas  Conference.  The  first  inter-allied  gas 
conference  was  held  in  Paris  on  September  16th,  and  consisted 


80  CHEMICAL  WARFARE 

of  American,  British,  French,  Italian,  and  Belgian  delegates. 
The  conference  busied  itself  mainly  with  questions  of  the 
medical  treatment  of  gassed  cases  and  of  defense  against  gas. 

Mustard  Gas.  The  principal  topic  under  consideration  at 
^  this  conference  was  the  effects  of  the  new  mustard  gas  first 
used  at  Ypres  against  the  British  on  the  nights  of  the  11th 
and  12th  of  July,  1917.  The  British  suffered  nearly  20,000 
casualties  from  this  gas  during  the  first  six  weeks  of  its  use, 
and  were  so  worried  over  it  that  the  start  of  the  attacks  carried 
out  later  in  the  fall  of  1917  against  Ypres  were  delayed  several 
days.  The  casualties  were  particularly  heavy  because  the 
smell  of  the  gas  was  entirely  new  and  not  unpleasant  and 
because  of  the  delayed  action  of  the  gas,  whereby  men  got  no 
indication  of  its  seriousness  until  4  to  8  hours  after  exposure. 
For  these  reasons  men  simply  took  shelter  from  the  bombard- 
ment without  putting  on  masks  or  taking  other  precautions.  As 
a  result  of  the  Paris  conference  a  long  cable  was  sent  to  the 
United  States  asking  among  other  things  that  immediate 
report  be  made  on  the  possibilities  of  producing  ethylene 
chlorhydrin,  one  of  the  essentials  in  the  manufacture  of  mus- 
tard gas  by  the  only  method  then  known. 

Within  two  weeks  after  this  conference,  there  occurred  an 
incident  which  illustrates  the  very  great  danger  in  taking 
the  views  of  any  one  man  unless  certain  that  he  is  in  a  position 
to  be  posted  on  all  sides  of  the  question  under  discussion.  A 
high  British  official  was  asked  what  he  had  heard  in  regard 
to  the  new  mustard  gas,  and  what  and  how  it  was  considered. 
He  said  with  emphasis  that  the  British  had  no  further  fear 
of  it  since  they  had  learned  what  it  was  and  how  to  take  care 
of  themselves  and  that  it  had  ceased  to  be  any  longer  a  problem 
with  them. 

Fries,  knowing  what  he  did,  was  convinced  that  this  did 
not  represent  the  attitude  of  the  British  authorities  who 
knew  what  the  gas  was  doing,  and  the  statement  was  not 
allowed  to  influence  the  American  Gas  Service  in  the  least. 
This  was  a  very,  fortunate  thing  as  events  later  proved.  It 
should  also  be  added  that  a  quite  similar  report  was  made 
by  a  French  officer  in  regard  to  mustard  gas  some  time  in  the 
month  of  October.     The  French  officer  had  more  reason  for 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE 


81 


his  attitude  than  the  British  officer  as  up  to  that  time  mustard 
gas  had  not  been  largely  used  against  the  French.  However, 
both  cases  simply  emphasize  the  danger  of  accepting  the  views 
of  any  man  who  has  seen  but  one  angle  of  a  problem  so  com- 
plicated as  gas  in  war. 

Training 

Training  in  Gas  Defense.     In  the  latter  part  of  October 
seventeen  young  engineer  officers,  who  had  just  arrived  in 


Fig.  9. — Destroying  Mustard  Gas  on  the  Battle  Field. 


France,  were  assigned  to  the  Gas  Service  and  were  promptly 
sent  to  British  Gas  Schools  for  training  in  mask  inspection, 
salvage  and  repair  and  in  training  men  to  wear  masks  and 
take  other  necessary  precautions  against  gas  in  the  field.  It 
was  also  necessary  at  this  time  to  establish  gas  training  in 
the  First  Division,  and  Captain  Boothby  was  assigned  to  that 
work. 

It  is  important  to  note  that  the  Gas  Service  had  to  begin 
operations  immediately  upon  its  organization  although  it  had 
almost  no  facilities  of  any  kind  to  work  with.    At  one  and  the 


82  CHEMICAL  WARFARE 

same  time  it  was  necessary  to  decide  upon  the  kinds  of  masks 
to  be  used  and  then  to  obtain  them;  to  decide  upon  methods  ^ 
of  training  troops  in  gas  defense  and  start  at  once  to  do  it;  ^ 
to  decide  upon  gases  to  be  used  and  manufactured  in  the 
United  States  and  then  obtain  and  send  the  necessary  data 
and  finally  to  decide  what  weapons  gas  troops  were  to  use  and 
to  purchase  those  weapons,  since  none  of  them  existed  in  the 
United  States.  Worse  still  no  one  in  the  United  States  was 
taking  any  interest  in  them. 

New  Mask.  About  November  1,  Major  Karl  Connell  of  the 
Medical  Department,  National  Guard  of  New  York,  reported 
for  duty  in  response  to  a  cablegram  that  had  been  sent  asking 
for  him  by  name.  It  was  intended  to  send  him  to  a  British 
School  to  learn  the  art  of  teaching  gas  defense.  However, 
learning  after  a  short  talk  with  him  that  he  had  been  interested 
in  making  masks  for  administering  anaesthesia,  there  was  at 
once  turned  over  to  him  samples  of  all  the  masks  in  use  by 
both  the  Allies  and  the  Germans,  with  a  view  to  getting  his 
ideas  for  a  new  mask.  Within  two  or  three  hours  he  suggested 
a  new  mask  having  a  metal  face  piece  with  sponge  rubber 
against  the  face  and  with  a  canister  to  be  carried  on  the  back 
of  the  head. 

At  that  early  date  it  was  realized  that  a  new  mask  must 
be  invented  which  would  be  far  more  comfortable  and  give 
better  vision  than  the  British  respirators  adopted  for  use. 
Connell,  thirty-six  hours  after  reporting,  had  so  far  developed 
his  idea  that  he  was  sent  to  Paris  to  make  the  first  model, 
which  he  succeeded  in  doing  in  about  three  weeks.  This  -first 
mask  was  good  enough  to  risk  testing  in  a  high  concentration 
of  chlorine  and  while  it  leaked  to  some  extent  it  indicated  that 
the  idea  was  sound.  The  problem  then  was  to  perfect  the  mask 
and  determine  how  it  could  be  produced  commercially  on  the 
large  scale  necessary  to  equip  an  army. 

Since  the  British  at  this  time  and  practically  throughout 
the  war  were  much  ahead  of  the  French  in  all  phases  of  gas 
warfare,  Connell  was  sent  to  London.  There  he  succeeded  in 
getting  additional  models  in  such  shape  that  one  of  them 
was  sent  to  the  United  States  during  the  first  few  days  of 
January,  1918.     Connell's  work  and  experiments  were  con- 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE  83 

tinned  so  successfully  that  after  a  model  had  been  submitted 
to  the  General  Staff,  as  well  as  to  General  Pershing  himself,  one 
thousand  were  ordered  to  be  made  early  in  May  with  a  view 
to  an  extensive  field  test  preparatory  to  their  adoption  for 
general  use  in  the  United  States  Army. 

In  this  connection,  during  November,  1917,  a  letter  was 
written  to  the  United  States  stating  that  while  the  Gas  Service 
in  France  insisted  an  the  manufacture  of  British  respirators 
exactly  as  the  British  were  making  them,  they  desired  to  have 
experiments  pushed  On  a  more  comfortable  mask  to  meet  the 
future  needs  of  the  Army. 

The  following  four  principles  were  set  down  in  that  letter: 
(a)  That  the  mask  must  give  protection  and  that  experience 
had  shown  that  suitable  protection  could  only  be  obtained  by 
drawing  the  air  through  a  box  filled  with  chemicals  and  charcoal. 
(6)  That  there  must  be  clear  vision  and  that  experience  to  date 
indicated  that  the  Tissot  method  of  bringing  the  inspired  air 
over  the  eye  pieces  was  by  far  the  best,  (c)  That  the  mask 
must  be  as  comfortable  as  compatible  with  reasonable  protec- 
tion, and  that  this  meant  the  mouthpiece  and  noseclip  must  be 
omitted,  {d)  That  the  mask  must  be  as  nearly  fool  proof  as  it 
could  be  made.  That  is,  it  should  be  of  quick  and  accurate 
adjustment,  in  the  dark  or  in  the  trenches,  and  be  difficult  to 
disarrange  or  injure  once  in  position. 

Gas  Training  and  Battle  of  Picardy  Plains.  On  March  21,' 
1918,  as  is  known  to  everyone,  the  Germans  began  their  great 
drive  from  Cambrai  across  the  Picardy  Plains  to  Amiens.  While 
the  battle  was  expected  it  came  as  a  complete  surprise  so  far 
as  the  tactics  used,  and  the  extent  and  force  of  the  attack, 
were  concerned.  Lieutenant  Colonel  G.  N.  Lewis,  who  had  /L^ 
been  sent  about  March  1  to  British  Gas  Schools,  and  had  been 
assigned  to  one  of  the  schools  run  by  the  Canadians,  was  thus 
just  on  the  edge  of  the  attack.  This  gave  him  an  opportunity 
to  actually  observe  some  of  that  attack  and  to  learn  from 
eye-witnesses  a  great  deal  more.  The  school,  of  course,  was 
abandoned  hurriedly  and  the  students  ordered  back  to  their 
•ations.  Lewis  submitted  two  brief  reports  covering  facts 
earing  on  the  use  of  gas  and  smoke  by  the  Germans.  These 
reports  exiiibited  sucli  a  grasp  of  gas  and  smoke  battle  tactics 


~       D( 


84  CHEMICAL   WARFARE 

that  he  was  immediately  ordered  to  headquarters  as  assistant 
on  the  Defense  side  of  gas  work,  that  is,  on  training  in  gas 
defense.  Up  to  that  time  no  one  had  been  able  to  organize 
the  Defensive  side  of  gas  work  in  the  way  it  was  felt  it  must 
be  organized  if  it  were  to  prove  a  thorough  success.  A  month 
later  he  was  put  at  the  head  of  the  Gas  Defense  Section,  and 
in  two  months  he  had  put  the  Defense  Division  on  a  sound 
basis.  He  was  then  ordered  to  the  United  States  to  help  organize 
Gas  Defense  Training  there. 


Fig.  10. — Close  Burst  of  a  Gas  Shell.   'The  6th  Marines  in  the  Sommediene 
Sector  near  Verdun,  April  30,  1918. 

Cabled  Report  on  Picardy  Battle.  Based  partly  on  Colonel 
Lewis's  written  and  oral  reports,  and  also  on  information  con- 
tained in  Intelligence  dispatches  and  the  newspapers,  a  cable- 
gram of  more  than  300  words  was  drafted  reciting  the  main 
features  of  the  battle  so  far  as  they  pertained  to  the  use  of 
gas.  This  cablegram  ended  with  the  statement  that  ''the 
above  illustrates  the  tremendous  importance  of  comfort  in  a 
mask"  and  that  ''the  future  mask  must  omit  the  mouthpiece 
and  noseclip. " 

Keeping  the  General  Staff  Informed  of  Work.  In  the  early 
part  of  May,  1918,  the  Americans  arrived  in  the  vicinity  of 
Montdidier,  south  of  Amiens,  on  the  most  threatened  point  of 


THE-  CHEMICAL  WARFARE  SERVICE  IN  FRANCE  85 

the  western  front.  It  was  on  May  18,  1918,  that  the  Americans 
attacked,  took,  and  held  against  several  counter  attacks  the 
town  of  Cantigny.  Shortly  afterward  they  were  very  heavily 
shelled  with  mustard  gas  and  suffered  in  one  night  nearly 
900  casualties.  Investigation  showed  that  these  casualties  were 
due  to  a  number  of  causes  more  or  less  usual,  but  also  to  the 
fact  that  the  men  had  to  wear  the  mask  12  to  15  hours  if  they 
were  to  escape  being  gassed.  Such  long  wearing  of  the  British 
mask  with  its  mouthpiece  and  noseclip  is  practically  an  impos- 
sibility and  scores  became  gassed  simply  through  exhaustion 
and  inability  to  wear  the  mask. 

An  inspector  from  General  Headquarters  in  reporting  on 
supplies  and  equipment  in  the  First  Division,  stated  that  one 
of  the  most  urgent  needs  was  a  more  comfortable  mask.  The 
First  Division  suggested  a  mask  on  the  principles  of  the  new 
French  mask  which  was  then  becoming  known  and  which 
omitted  the  mouthpiece  and  noseclip.  The  efforts  of  the 
American  Gas  Service  in  France  to  perfect  a  mask  without 
a  mouthpiece  and  noseclip  were  so  well  known  and  so  much 
appreciated  that  they  did  not  even  call  upon  the  Gas  Service 
for  remark.  The  assistant  to  the  Chief  of  Staff  who  drew 
up  the  memorandum  to  the  Chief  simply  said  the  matter  was 
being  attended  to  by  the  Gas  Service.  This  illustrates  the 
value  of  keeping  the  General  Staff  thoroughly  informed  of 
what  is  being  done  to  meet  the  needs  of  the  troops  on  the 
firing  line. 

Then,  as  always,  it  was  urged  that  a  reasonably  good  mask 
was  far  more  desirable  than  the  delay  necessary  to  get  a  more 
perfect  one.  Based  on  thiBse  experiences  with  mask  develop- 
ment, the  authors  are  convinced  that  the  whole  tendency  of 
workers  in  general,  in  laboratories  far  from  the  front,  is  to 
over-estimate  the  value  of  perfect  protection  based  on  labora- 
tory standards.  It  is  difficult  for  laboratory  workers  to  realize 
that  battle  conditions  always  require  a  compromise  between 
perfection  and  getting  sometliing  in  time  for  the  battle.  It 
was  early  evident  to  the  Gas  Service  in  France  that  we  were 
sing,  and  would  continue  to  lose,  vastly  more  men  through 
emoval  of  masks  of  the  British  type,  due  to  discomfort  and 
xhaustion,  than  we  would  from  a  more  comfortable  but  less 


86  CHEMICAL  WARFARE 

perfect  mask.  In  other  words  when  protection  becomes  so 
much  of  a  burden  that  the  average  man  cannot  or  will  not 
stand  it,  it  is  high  time  to  find  out  what  men  will  stand,  and 
then  supply  it  even  at  the  expense  of  occasional  casualties. 
Protection  in  battle  is  always  relative.  The  only  perfect  pro- 
tection is  to  stay  at  home  on  the  farm.  The  man  who  cannot 
balance  protection  against  legitimate  risks  has  no  business  pass- 
ing on  arms,  equipment  or  tactics  to  be  used  at  tlie  Front. 

As  early  as  September,  1917,  gas  training  was  begun  in 
the  First  Division  at  Condrecourt.  This  training  school  became 
the  First  Corps  School.  Later  a  school  was  established  at  Langres 
known  as  the  Army  Gas  School  while  two  others  known  as 
the  Second  and  Third  Corps  Gas  Schools  were  established 
elsewhere.  The  first  program  of  training  for  troops  in  France 
provided  for  a  total  period  of  three  months.  Of  this,  two  days 
were  allowed  the  Gas  Service.  Later  this  was  reduced  to  six 
hours,  notwithstanding  a  vigorous  protest  by  the  Gas  Service. 
However,  following  the  first  gas  attacks  against  the  Americans 
with  German  projectors  in  March,  1918,  followed  a  little  later 
by  extensive  attacks  with  mustard  gas,  the  A.  E.  F.  Gas 
Defense  School-  was  estalilished  at  the  Experimental  Field. 
Arrangements  were  made  for  the  accommodation  of  200  officers 
for  a  six-day  course.  The  number  instructed  actually  averaged 
about  150,  due  to  the  feeling  among  Division  Commanders  that 
they  could  not  spare  quite  so  many  officers  as  were  required  to 
furnish  200  per  week. 

This  school  was  conducted  under  the  Commandant  of 
Hanlon  Field,  Lieutenant  Colonel  Hildebrand,  by  Captain  Bush 
of  the  British  Service.  This  Gas  Defense  School  became  one  of 
the  most  efficient  schools  in  the  A.  E.  F.,  and  was  developing 
methods  of  teaching  that  were  highly  successful  in  protecting 
troops  in  the  field. 

Failure  of  German  Gas.  The  losses  of  the  Americans  from 
German  gas  attacks  fluctuated  through  rather  wide  limits. 
There  were  times  in  the  early  days  during  training  when  this 
reached  65  per  cent  of  the  total  casualties.  There  were  other 
times  in  battle,  when  due  to  extremely  severe  losses  from 
machine  gun  fire  in  attacks,  that  the  proportion  of  gas  losses 
to  all  other  forms  of  casualties  was  very  small.     On  the  whole 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE 


87 


the  casualties  from  gas  reached  27.3  of  all  casualties.  This 
small  percentage  was  due  solely  to  the  fact  that  when  the 
Americans  made  their  big  attacks  at  San  Mihiel  and  the 
Argonne,  the  German  supply  of  gas  had  run  very  low.  This 
was  particularly  true  of  the  supply  of  mustard  gas. 

Fries  was  at  the  front  visiting  the  Headquarters  of  the 
First  Army  and  the  Headquarters  of  the  1st,  3d,  and  5th 
Corps  from  two  days  before  the  beginning  of  the  battle  of 
the  Argonne  to  four  days  afterwards.     He  watched  reports 


Fig.  11. — German  Gas  Alarms. 

of  the  battle  on  the  morning  of  the  attack  at  the  Army  Head- 
quarters and  later  at  the  1st,  5th  and  3d  Corps  headquarters 
in  the  order  named.  No  reports  of  any  gas  casualties  were 
received.  This  situation  continued  throughout  the  day.  It 
was  so  remarkable  that  he  told  the  Chief  of  Staff  he  could 
attribute  the  German  failure  to  use  gas  to  only  one  of  two 
possible  conditions;  first,  the  enemy  was  out  of  gas;  second, 
he  was  preparing  some  master  stroke.  The  first  proved  to  be 
the  case  as  examination  after  the  Armistice  (6f  German  shell 
dumps  captured  during  the  advance  reveale^  less  than  1  per 


X 


88  CHEMICAL  WARFARE 

cent  of  mustard  gas  shell.  Even  under  these  circumstances 
the  Germans  caused  quite  a  large  number  of  gas  casualties 
during  the  later  stages  of  the  fighting  in  the  Argonne-Meuse 
sector. 

Evidently  the  Germans,  immediately  after  the  opening  of 
the  attack,  or  more  probably  some  days  before,  began  to  gather 
together  all  available  mustard  gas  and  other  gases  along  the 
entire  western  battle  front,  and  ship  them  to  the  American 
sector.  This  conclusion  seems  justified  because  the  enemy 
never  had  a  better  chance  to  use  gas  effectively  than  he  did 
the  first  three  or  four  days  of  the  Argonne  fight,  and  knowing 
this  fact  he  certainly  would  never  have  failed  to  use  the  gas 
if  it  had  been  available.  Had  he  possessed  50  per  cent  of  his 
artillery  shell  in  the  shape  of  mustard  gas,  our  losses  in  the 
Argonne-Meuse  fight  would  have  been  at  least  100,000  more 
than  it  was.  Indeed,  it  is  more  than  possible  we  would  never 
have  succeeded  in  taking  Sedan  and  Mezieres  in  the  fall  of  1918. 

Officers'  Training  Cajnp.  The  first  lot  of  about  100  officers 
were  sent  to  France  in  July,  1918,  with  only  a  few  days'  train- 
ing, and  in  some  cases  with  no  training  at  all.  Accordingly, 
arrangements  were  made  to  train  these  men  in  the  duties  of 
the  soldier  in  the  ranks,  and  then  as  officers.  Their  training 
in  gas  defense  and  offense  followed  a  month  of  strenuous  work 
along  the  above  mentioned  lines. 

This  camp  was  established  near  Hanlon  (Experimental) 
Field,  at  a  little  town  called  Choignes.  The  work  as  laid  out 
included  squad  and  company  training  for  the  ordinary  soldier, 
each  officer  taking  turns  in  commanding  the  company  at  drill. 
They  were  given  work  in  map  reading  as  well  as  office  and 
company  administration. 

This  little  command  was  a  model  of  cleanliness  and  military 
discipline,  and  attracted  most  favorable  comment  from  staff 
officers  on  duty  at  General  Headquarters  less  than  two  miles 
distant.  Just  before  the  Armistice  arrangements  were  made 
to  transfer  this  work  to  Chignon,  about  25  miles  southeast  of 
Tours,  where  ample  buildings  and  grounds  were  available  to 
carry  out  not  alone  training  of  officers  but  of  soldiers  along 
the  various  lines  of  work  they  would  encounter,  from  the 
handling  of  a  squad,  to  being  Chief  Gas  Officer  of  a  Division. 


THE' CHEMICAL  WARFARE  SERVICE  IN  FRANCE  89 

Educating  the  Army  in  the  Use  of  Gas.  As  has  been 
remarked  before,  the  Medical  Department  in  starting  the  manu- 
facture of  gas  masks  and  other  defensive  appliances,  and  the 
Bureau  of  Mines  in  starting  researches  into  poisonous  gases 
as  well  as  defensive  materials,  were  the  only  official  bodies  who 
early  interested  themselves  in  gas  warfare.  Due  to  this  early 
work  of  the  Bureau  of  Mines  and  the  Medical  Department  in 
starting  mask  manufacture  as  well  as  training  in  the  wearing 
of  gas  masks,  the  defensive  side  of  gas  warfare  became  known 
tlu'oughout  the  army  very  far  in  advance  of  the  offensive  side. 
On  the  other  hand,  since  the  Ordnance  Department,  which  was 
at  first  charged  with  the  manufacture  of  poisonous  gases,  made 
practically  no  move  for  months,  the  offensive  use  of  gas  did 
not  become  known  among  United  States  troops  until  after  they 
landed  in  France. 

Moreover,  no  gas  shell  was  allowed  to  be  fired  by  the 
artillery  in  practice  even  in  France,  so  that  all  the  training 
in  gas  the  artillery  could  get  until  it  went  into  the  line  was 
defensive,  with  lectures  on  the  offensive. 

The  work  of  raising  gas  troops  was  not  begun  until  the  late 
fall  of  1917  and  as  their  work  is  highly  technical  and  dangerous, 
they  were  not  ready  to  begin  active  work  on  the  American 
front  until  June,  1918. 

By  that  time  the  army  was  getting  pretty  well  drilled  in 
gas  defense  and  despite  care  in  that  respect  were  getting  into 
a  frame  of  mind  almost  hostile  to  the  use  of  gas  by  our  own 
troops.  Among  certain  staff  officers,  as  well  as  some  com- 
manders of  fighting  units,  this  hostility  was  outspoken  and 
almost  violent. 

Much  the  hardest,  most  trying  and  most  skillful  work 
lequired  of  Chemical  Warfare  Service  officers  was  to  persuade 
such  Staffs  and  Commanders  that  gas  was  useful  and  get  them 
to  permit  of  a  demonstration  on  their  front.  Repeatedly 
Chemical  Warfare  Service  officers  on  Division  staffs  were  told 
by  officers  in  the  field  that  they  had  nothing  to  do  with  gas 
in  offense,  that  they  were  simply  defensive  officers.  And  yet 
no  one  else  knew  anything  about  the  use  of  gas.  Gradually, 
however,  by  constantly  keeping  before  the  General  Staff  and 
^-qthers  the  results  of  gas  attacks  by  the  Germans,  by  the  British, 


90  CHEMICAL  WARFARE 

by  the  French,  and  by  ourselves,  headway  was  made  toward 
getting  our  Armies  to  use  gas  effectively  in  offense. 

But  so  slow  was  this  work  that  it  was  necessary  to  train 
men  particularly  how  to  appeal  to  officers  and  commanders 
on  the  subject.  Indeed  the  following  phrase,  used  first  by 
Colonel  Mayo-Smith,  became  a  watchword  throughout  the 
Service  in  the  latter  part  of  the  war — ''Chemical  Warfare 
Service  officers  have  got  to  go  out  and  sell  gas  to  the  Army." 
In  other  words  we  had  to   adopt  much  the  same  means  of 


Fig.  12. — A  Typical  Shell  Dump  near  the  Front. 

making  gas  known  that  the  manufacturer  of  a  new  article 
adopts  to  make  a  thing  manufactured  by  him  known  to  the 
public. 

This  work  was  exceedingly  trying,  requiring  great  skill, 
great  patience  and  above  all  a  most  thorough  knowledge  of 
the  subject.  As  illustrating  some  of  these  difficulties,  the 
Assistant  Chief  of  Staff,  G-3  (Operations)  of  a  certain  Ameri- 
can Corps  refused  to  consider  a  recommendation  to  use  gas 
on  a  certain  point  in  the  battle  of  the  Argonne  unless  the 
gas  officer  would  state  in  writing  that  if  the  gas  was  so  used 
it  could  not  possibly  result  in  the  casualty  of  a  single  American 
soldier.     Such  an  attitude  was  perfectly  absurd. 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE  91 

The  Infantry  always  expects  some  losses  from  our  own  high 
explosive  when  following  a  barrage,  and  though  realizing  the 
tremendous  value  of  gas,  this  staff  officer  refused  to  use  it 
without  an  absolute  guarantee  in  writing  that  it  could  not 
possibly  injure  a  single  American  soldier.  Another  argument 
often  used  was  tliat  a  gas  attack  brought  retaliatory  fire  on 
the  front  where  the  gas  was  used.  Such  objectors  were  narrow 
enough  not  to  realize  that  the  mere  fact  of  heavy  retaliation 
indicated  the  success  of  the  gas  on  the  enemy  for  everyone 
knows  an  enemy  does  not  retaliate  against  a  thing  which  does 
not  worry  him. 

But  on  the  other  hand,  when  the  value  of  gas  troops  had 
become  fully  known,  the  requests  for  them  were  so  great  that 
a  single  platoon  had  to  be  assigned  to  brigades,  and  sometimes 
even  to  whole  Divisions.  Thus  it  fell  to  the  Lieutenants  com- 
manding these  platoons  to  confer  with  Division  Commanders 
and  Staffs,  to  recommend  how,  when  and  where  to  use  gas, 
and  do  so  in  a  manner  which  would  impress  the  Commanding 
General  and  the  Staff  sufficiently  to  allow  them  to  undertake 
the  job.  That  no  case  of  failure  has  been  reported  is  evidence 
of  the  splendid  ability  of  these  officers  on  duty  with  the  gas 
troops.  Efficiency  in  the  big  American  battles  was  demanded 
to  an  extent  unheard  of  in  peace,  and  had  any  one  of  these 
officers  made  a  considerable  failure,  it  certainly  would  have 
been  reported  and  Fries  would  have  heard  of  it. 

Equally  hard,  and  in  many  cases  even  more  so,  was  the 
work  of  the  gas  officers  on  Division,  Corps  and  Army  Staffs, 
who  handled  the  training  in  Divisions,  and  who  also  were 
required  to  recommend  the  use  of  gas  troops,  the  use  of  gas 
in  artillery  shell  and  in  grenades,  and  the  use  of  smoke  by  the 
infantry  in  attack.  However,  the  success  of  the  Chemical 
AVarfare  Service  in  the  field  with  these  Staff  officers  was  just 
as  great  as  with  the  Regiment. 

To  the  everlasting  credit  of  those  Staff  Officers  and  the 
Officers  of  the  Gas  Regiment  from  Colonel  Atkisson  down,  both 
Staff  Gas  officers  and  officers  of  the  Gas  Regiment  worked 
together  in  the  fullest  harmony  with  the  single  object  of  defeat- 
ing the  Germans. 


92 


CHEMICAL  WARFARE 


Chemical  Warfare  Troops 

Chemical  Warfare  troops  were  divided  into  two  distinct 
divisions — gas  regiments  and  staff  troops. 

Staff  Troops.  The  staff  troops  of  the  Chemical  Warfare 
Service  performed  all  work  required  of  gas  troops  except  that 
of  actual  fighting.  They  handled  all  Chemical  Warfare  Service 
supplies  from  the  time  they  were  unloaded  from  ships  to  the 


Fig.  13. — Firing  a  155-Millimeter  Howitzer. 

The  men  are  wearing  gas  masks  to  keep  out  the  enemy  gas  fired  at  them  in  Oct.,  1918. 

time  they  were  issued  to  the  fighting  troops  at  the  front, 
whether  the  fighting  troops  were  Chemical  Warfare  or  any 
other.  They  furnished  men  for  clerical  and  other  services  with 
the  Army,  Corps  and  Division  Gas  Officers,  and  they  manu- 
factured poisonous  gases,  filled  gas  shells  and  did  all  repairing 
and  altering  of  gas  masks.  Though  these  men  received  none 
of  the  glamour  or  glory  that  goes  with  the  fighting  men  at 
the  front,  yet  they  performed  services  of  the  most  vital  kind 
and  in  many  cases  did  work  as  dangerous  and  hair  raising 
as  going  over  the  top  in  the  face  of  bursting  shell  and  scream- 
ing machine  gun  bullets. 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE  93 

Think  of  the  intense  interest  these  men  must  have  felt  when 
carrying  from  the  field  of  battle  to  the  laboratory  or  experi- 
mental field,  shell  loaded  with  strange  and  unheard  of  com- 
pounds and  which  might  any  moment  burst  and  end  forever 
their  existence  !  Or  watch  them  drilling  into  a  new  shell  know- 
ing not  what  powerful  poison  or  explosive  it  might  contain 
or  what  might  happen  when  the  drill  '^went  through 'M 

And  again  what  determination  it  took  to  work  12  or  16 
hours  a  day  way  back  at  the  depots  repairing  or  altering  masks, 
and,  as  was  done  at  Chateroux,  alter  and  repair  15,000  masks 
a  day  and  be  so  rushed  that  at  times  they  had  a  bare  day's 
work  of  remodeled  masks  ahead.  But  they  kept  ahead  and 
to  the  great  glory  of  these  men  no  American  soldier  ever  had 
to  go  to  the  front  without  a  mask.  And  what  finer  work 
than  that  of  these  men  who,  in  the  laboratory  and  testing  room, 
toyed  with  death  in  testing  unknown  gases  with  American  and 
foreign  masks  even  to  the  extent  of  applying  the  gases  to  their 
own  bodies. 

Heroic,  real  American  work,  all  of  it  and  done  in  real 
American  style  as  part  of  the  day's  work  without  thought  of 
glory  and  without  hope  of  reward. 

The  First  Gas  Regiment.  In  the  first  study  of  army  organ- 
ization made  by  the  General  Staff  it  was  decided  to  recom- 
mend raising  under  the  Chief  of  Engineers  one  regiment  of  six 
companies  of  gas  troops. 

Shortly  after  the  cable  of  August  17,  1917,  was  sent  stating 
that  Lieut.  Colonel  Fries  would  be  made  Chief  of  the  Gas 
Service,  the  War  Department  promoted  him  to  be  Colonel  of 
the  30th  Engineers  which  later  became  the  First  Gas  Regiment. 
At  almost  the  same  time.  Captain  Atkisson,  Corps  of  Engineers, 
was  appointed  Lieut.  Col.  of  the  Regiment.  Although  Colonel 
Fries  remained  the  nominal  Commander  of  the  regiment,  he 
never  acted  in  that  capacity,  for  his  duties  as  Chief  of  the  Gas 
Service  left  him  neither  time  nor  opportunity.  All  the  credit  for 
raising,  training,  and  equipping  the  First  Gas  Regiment  belongs 
to  Colonel  E.  J.  Atkisson  and  the  officers  picked  by  him. 

Immediately  upon  the  formation  of  the  Gas  Service,  the 
Chief  urged  that  many  more  than  six  companies  of  gas  troops 
should  be  provided.    These  recommendations  were  repeated  and 


94  CHEMICAL  WARFARE 

urged  for  the  next  two  months  or  until  about  the  first  of 
November,  when  it  became  apparent  that  an  increase  could 
not  be  obtained  at  that  time  and  that  any  further  urging 
would  only  cause  irritation.  The  matter  was  therefore  dropped 
until  a  more  auspicious  time  should  arrive.  This  arrived  the 
next  spring  when  the  first  German  projector  attack  against 
United  States  troops  produced  severe  casualties,  exactly  as  had 
been  forecasted  by  the  Gas  Service.  About  the  middle  of 
March,  1918,  an  increase  from  two  battalions  to  six  battalions 


Fig.  14. — Receiving  and  Transmitting  Data  for  Firing  Gas  Shell  while  Wearing 
Gas  Masks.     Eiattlefield  of  the  Argonne,  October,  1918. 

(eighteen  companies)  was  authorized.  A  further  increase  to 
three  regiments  of  six  battalions  each  (a  total  of  iifty-four 
companies)  was  authorized  early  in  September,  1918,  after 
the  very  great  value  of  gas  troops  had  been  demonstrated  in 
the  fight  from  the  Marne  to  the  Vesle  in  July. 

No  Equipment  for  Gas  Troops.  About  the  first  of  December 
a  cablegram  was  received  from  the  United  States  stating  that 
due  to  lack  of  equipment  the  various  regiments  of  special 
engineers  recently  authorized,  including  the  30th  (Gas  and 
Flame)  would  not  be  organized  until  the  spring  of  1918.  An 
urgent  cablegram  was  then  sent  calling  attention  to  the  fact 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE  95 

that  gas  troops  were  not  service  of  supply  troops  but  first 
line  fighting  troops,  and  consequently  that  they  should  be 
raised  and  trained  in  time  to  take  the  field  with  the  first 
Americans  going  into  the  line.  At  this  same  time  the  30th 
regiment  was  given  early  priority  by  the  General  Staff,  A.  E.  F., 
on  the  priority  lists  for  troop  shipments  from  the  United  States. 
The  raising  of  the  first  two  companies  was  then  continued  under 
Colonel  Atkisson  at  the  American  Univorsity  in  Washington. 

About  January  15  word  was  received  that  the  Headquarters 
of  the  regiment  and  the  Headquarters  of  the  First  Battalion 
together  with  Companies  A  and  B  of  the  30th  Engineers  (later 
the  First  Gas  Regiment)  were  expected  to  arrive  very  soon. 
Some  months  prior  General  Foulkes,  Chief  of  the  British  Gas 
Service  in  the  field,  had  stated  that  he  would  be  glad  to  have 
the  gas  troops  assigned  to  him  for  training.  It  was  agreed 
that  the  training  should  include  operations  in  the  front  line 
for  a  time  to  enable  the  American  Gas  Troops  to  carry  on 
gas  operations  independently  of  anyone  else  and  with  entire 
safety  to  themselves  and  the  rest  of  the  Army. 

Due  to  the  fact  that  the  British  were  occupying  their  gas 
school,  the  British  General  Headquarters  were  a  little  reluctant 
to  take  the  American  troops  Feb.  1.  However,  General  Foulkes 
made  room  for  the  American  troops  by  moving  his  own  troops 
out.  He  then  placed  his  best  officers  in  charge  of  their  training 
and  at  all  times  did  everything  in  his  power  to  help  the 
American  Gas  Troops  learn  the  gas  game  and  get  sufficient 
.supplies  to  operate  with.  Colonel  Hartley,  Assistant  to  General 
Foulkes,  also  did  everything  he  could  to  help  the  American 
Gas  Service.  These  two  officers  did  more  than  any  other 
foreign  officers  in  France  to  enable  the  Chemical  Warfare 
Service  to  make  the  success  it  did. 

Second  Battle  of  the  Marae.  The  Chief  of  the  Gas  Service, 
following  a  visit  to  the  British  Gas  Headquarters,  and  the 
Headquarters  of  the  American  2d  Corps  then  operating  with 
the  British,  arrived  on  the  evening  of  July  17,  1918,  at  1st 
Corps  Headquarters  at  La  Ferte  sous  Jouarre  about  10  miles 
southeast  of  Chateau-Thierry. 

Two  companies  of  the  First  Gs^s  Regiment  would  have  been 
ready  in  48  hours  to  put  off  a  projector  attack  against  an 


96  CHEMICAL  WARFARE 

excellent  target  just  west  of  Belleau  Wood  had  not  the  2d  battle 
of  the  Marne  opened  when  it  did.  It  is  said  that  General 
Foch  had  kept  this  special  attack  so  secret  that  the  First 
American  Corps  Commander  knew  it  less  than  48  hours  prior 
to  the  hour  set  for  its  beginning.  Certainly  the  Chief  of  the 
Gas  Service  knew  nothing  of  it  until  about  9  :00  p.m.,  the  night 
of  July  17th.  Consequently  the  gas  attack  was  not  made.  At 
that  time  so  little  was  known  of  the  usefulness  of  gas  troops 
that  they  were  started  on  road  work.  At  Colonel  Atkisson's 
suggestion  that  gas  troops  could  clean  out  machine  gun  nests, 
he  was  asked  to  visit  the  First  Corps  headquarters  and  take 
up  his  suggestion  vigorously  with  the  First  Corps  Staff. 

Attacking  Machine  Gun  Nests.  Thereupon  the  Gas  troops 
were  allowed  to  try  attacking  machine  gun  nests  with  phos- 
phorus and  thermite.  This  work  proved  so  satisfactory  that 
not  long  afterwards  the  General  Staff  authorized  an  increase 
in  gas  troops  from  18  companies  to  54  companies,  to  be  formed 
into  three  regiments  of  two  battalions  each.  The  6  companies 
in  France  did  excellent  work  with  smoke  and  thermite  during 
all  the  second  battle  of  the  Marne  to  the  Vesle  river,  where 
by  means  of  smoke  screens  they  made  possible  the  crossing  of 
that  river  and  the  gaining  of  a  foothold  on  the  north  or 
German  side. 

With  the  assembling  of  American  troops  in  the  sector  near 
Verdun  in  September,  1918,  the  gas  troops  were  all  collected 
there  with  the  exception  of  one  or  two  companies  and  took 
a  very  active  part  in  the  capture  of  the  St.  Mihiel  salient.  It 
was  at  this  battle  that  the  Chemical  Warfare  Service  really 
began  to  handle  offensive  gas  operations  in  the  way  they  should 
be  handled.  Plans  were  drawn  for  the  use  of  gas  and  smoke 
by  artillery  and  gas  troops  both.  The  use  of  high  explosives 
in  Liven 's  bombs  was  also  planned.  Those  plans  were  properly 
co-ordinated  with  all  the  other  arms  of  the  service  in  making 
the  attack.  Gas  was  to  be  used  not  alone  by  gas  troops  but 
by  the  artillery.  Plans  were  made  so  that  the  ditjferent  kinds 
of  gases  would  be  used  where  they  would  do  the  most  good. 
While  these  plans  and  their  execution  were  far  from  perfect, 
they  marked  a  tremendous  advance  and  demonstrated  to  every- 


THi:  CHEMICAL  WARFARE  SERVICE  IN  FRANCE 


97 


one  the  possibilities  that  lay  in   gas  and  smoke  both  with 
artillery  and  with  gas  troops. 

Following  the  attack  on  the  St.  Mihiel  salient,  came  the 
battle  of  the  Argonne,  where  plans  were  drawn  as  before, 
using  the  added  knowledge  gained  at  St.  Mihiel.  The  work 
was  accordingly  more  satisfactory.  However,  the  attempt  to 
cover  the  entire  American  front  of  nine  divisions  with  only  six 
companies  proved  too  great  a  task.  Practically  all  gas  troops 
were  put  in  the  front  line  the  morning  of  the  attack.  Due 
to    weather    conditions    they    used    mostly    phosphorus    and 


Fig.  15. — Setting  Up  a  Smoke  Barrage  with  Smoke  Pots. 


thermite  with  4  inch  Stokes '  mortars.  Having  learned  how  useful 
these  were  in  taking  machine  gun  nests,  plans  were  made  to 
have  them  keep  right  up  with  the  Infantry.  This  they  did 
in  a  remarkable  manner  considering  the  weight  of  the  Stokes' 
mortar  and  the  base  plates  and  also  that  each  Stokes*  mortar 
bomb  weighed  about  25  pounds.  There  were  cases  where 
they  carried  these  mortars  and  bombs  for  miles  on  their  backs, 
while  in  other  cases  they  used  pack  animals. 

Not  expecting  the  battle  to  be  nearly  continuous  as  it  was 
for  three  weeks,  the  men,  as  before  stated,  were  all  put  in  the 
front  line  the  morning  of  the  attack.     This  resulted  in  their 


98  CHEMICAL  WARFARE 

nearly  complete  exhaustion  the  first  week,  since  they  fought 
or  marched  day  and  night  during  nearly  the  whole  time.    Tak- 
ing a  lesson  from  this,  in  later  attacks  only  half  the  men 
were  put  in  the  line  in  the  first  place,  no  matter  if  certain 
sectors  had  to  be  omitted.    Fully  as  good  results  were  obtained 
because,   as  the  men  became  worn  out,   fresh   ones  were  sent 
in  and  the  others  given  a  chance  to  recuperate.    Officers  relate 
many  different  occurrences  showing  the  discipline  and  char- 
acter of  these  gas  troops.    On  one  occasion  where  a  battalion 
of  infantry  was  being  held  up  by  a  machine  gun  nest,  volun- 
teers were  called  for.     Only  two  men,  both  from  the  gas  regi- 
ment,  volunteered  though  they  were  joined   a  little  later  by 
two  others  from  the  same  regiment,  and  these  four  took  the 
guns.     While  it  was  not  considered  desirable  for  gas  troops 
to  attempt  to  take  prisoners,  yet  the  regiment  took  quite  a 
number,  due  solely  to  the  fact  that  they  were  not  only  with 
the  advancing  infantry  but  at  times  actually  in  front  of  it. 
On  another  occasion  a  gas  officer,  seeing  a  machine  gun  bat- 
talion badly  shot  up  and  more  or  less  rattled,  took  command 
and  got  them  into  action  in  fine  shape. 
(^'     At  this  stage  the  Second  Army  was  formed  to  the  southeast 
\  of  Verdun  and  plans   were   drawn   for   a   big   attack   about 
J  November  14.     The  value  of  gas  troops  was  appreciated  so 
(^much  that  the  Second  Army  asked  to  have  British  gas  troops 
y  assigned  to  them  since  no  American  gas  troops  were  available. 
I   Accordingly  in  response  to  a  request  made  by  the  American 
General  Headquarters,  the  British  sent  10  companies  of  their 
\  gas  troops.    These  reached  the  front  just  before  the  Armistice, 
and  hence  were  unable  to  carry  out  any  attacks  there. 

This  short  history  of  the  operations  of  the  First  Gas  Regi- 
ment covers  only  the  high  spots  in  its  organization  and  work. 
It  covers  particularly  its  early  troubles,  as  those  are  felt  to 
be  the  ones  most  important  to  have  in  mind  if  ever  it  be 
necessary  again  to  organize  C.  W.  S.  troops  on  an  extensive 
scale.  The  Regiment  engaged  in  nearly  200  separate  actions 
with  poisonous  gases,  smoke  and  high  explosives,  and  took 
part  in  every  big  battle  from  the  second  battle  of  the  Marne 
to  the  end  of  the  War.  They  were  the  first  American  troops 
to   train  with   the   British,    and  were   undoubtedly   the   first 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE  99 

American  troops  to  take  actual  part  in  fighting  the  enemy 
as  they  aided  the  British  individually  and  as  entire  units  in 
putting  off  gas  attacks,  in  February  and  March,  1918.  It  would 
be  a  long  history  itself  to  recite  the  actions  in  which  the  First 
Gas  Regiment  took  part  and  in  which  it  won  distinction.^ 

No  better  summary  of  the  work  of  this  Regiment  can  be 
written  than  that  of  Colonel  Atkisson  in  the  four  concluding 
paragraphs  of  his  official  report  written  just  after  the 
Armistice : 

"The  First  Gas  Regiment  was  made  up  largely  of  volunteers — 
volunteers  for  this  special  service.  Little  was  known  of  its  character 
when  the  first  information  was  sent  broadcast  over  the  United  States, 
bringing  it  to  the  attention  of  the  men  of  our  country.  The  keynote 
of  this  information  was  a  desire  for  keen,  red-blooded  men  who  wanted 
to  fight.  They  came  into  it  in  the  spirit  of  a  fighting  unit,  and  were 
ready,  not  only  to  develop,  but  to  make  a  new  service.  No  effort  was 
spared  to  make  the  organization  as  useful  as  the  strength  of  the  limited 
personnel  allowed. 

"The  first  unit  to  arrive  in  France  moved  to  the  forward  area 
within  eight  weeks  of  its  arrival,  and,  from  that  time,  with  the  excep- 
tion of  four  weeks,  was  continuously  in  forward  areas  carrying  on 
operations.  The  third  and  last  unit  moved  forward  within  six  weeks 
of  its  arrival  in  France,  and  was  continuously  engaged  until  the  signing 
of  the  Armistice. 

"That  the  regiment  entered  the  fight  and  carried  the  methods 
developed  into  execution  where  they  would  be  of  value,  is  witnessed 
by  the  fact  that  over  thirty-five  percent  of  the  strength  of  the  unit 
became  casualties. 

"It  is  only  fitting  to  record  the  spirit  and  true  devotion  which 
prompted  the  oflScers  and  men  who  came  from  civil  life  into  this 
Regiment,  mastered  the  details  of  this  new  service,  and,  through  their 
untiring  efforts  and  utter  disregard  of  self,  made  possible  any  success 
which  the  Regiment  may  have  had.  It  was  truly  in  keeping  with  the 
high  ideals  which  have  prompted  our  entire  Army  and  Country  in  this 
conflict.  They  made  the  motto  of  'Service,'  a  real,  living,  inspiring 
thing."  , 

^  Story  of  the  First  Gas  Rojjiment,  James  T.  Addison.  Houghton  Mifflin 
Co.,  1919. 


100  CHEMICAL  WARFARE 


Supply 

As  previously  stated  it  was  decided  early  that  the  Chemical 
Warfare  Service  should  have  a  complete  supply  service  includ- 
ing purchase,  manufacture,  storage  and  issue,  and  accordingly 
separate  supply  depots  were  picked  out  for  the  Gas  Service 
early  in  the  fall  by  Col.  Crawford.  Where  practicable  these 
were  located  in  the  same  area  as  all  other  depots  though  in 
one  instance  the  French  forced  the  Gas  Service  to  locate  its 
gas  shell  and  bomb  depot  some  fifteen  miles  from  the  general 
depots  through  an  unreasonable  fear  of  the  gas. 

Manufacture  of  Gases.  Due  to  the  time  required  and  the 
cost  of  manufacturing  gases,  an  early  decision  became  impera- 
tive as  to  what  gases  should  be  used  by  the  Americans,  and 
into  what  shells  and  bombs  they  should  be  filled.  As  there 
was  no  one  else  working  on  the  subject  the  sole  responsibility 
fell  upon  the  Chief  of  the  Gas  Service.  The  work  was  further 
complicated  by  the  fact  that  the  British  and  French  did  not 
agree  upon  what  gases  should  be  used.  The  British  condemned 
viciously  Vincennite  (hydrocyanic  acid  gas  with  some  added 
ingredients)  of  the  French,  while  the  French  stated  that  chloro- 
picrin,  used  by  the  British  principally  as  a  lachrymator,  was 
worthless.  Fries  felt  the  tremendous  responsibility  that  rested 
upon  him  and  finally  after  much  thought  and  before  coming  to 
any  conclusion,  wrote  the  first  draft  of  a  short  paper  on  gas  war- 
fare. In  that  paper  he  took  up.  the  tactical  uses  to  which  gases 
might  be  put  and  then  studied  the  best  and  most  available  gases 
to  meet  those  tactical  needs. 

Without  stating  further  details  it  was  decided  to  recom- 
mend the  manufacture  and  use  of  chlorine,  phosgene,  chloro- 
picrin,  bromoacetone  and  mustard  gas.  As  the  gas  service  was 
also  charged  with  handling  smoke  and  incendiary  materials, 
smoke  was  prescribed  in  the  proportion  of  5  per  cent  of  the 
total  chemicals  to  be  furnished.  The  smoke  material  decided 
upon  was  white  phosphorus. 

The  paper  on  Gas  Warfare"  was  then  re-drafted  and  sub- 
mitted to  the  French  and  British  and  written  up  in  final  form 
perscribing  the  gases  above  mentioned  on  October  26.    Follow- 


THE  CHEMICAL  WARFARE  SERVICE  IN  fMNjCK     \  JjOj.' 

ing  this  a  cable  was  drawn  and  submitted  to  the  General  Staff. 
After  many  conferences  and  some  delay  the  cable  went  forward 
on  November  3. 

Cable  268,  November  4,  1917 

Paragraph  12.  For  cliief  of  Ordnance.  With  reference  to  para- 
graph 2  my  cablegram  181,  desire  prompt  information  as  to  whether 
recommendation  is  approved  that  phosgene,  chloropicrin,  hydrocyanic 
acid,  and  chlorine  be  purchased  in  France  or  England  and  filling  plants 
established  in  France  for  filling  shells  and  bombs  with  those  gases. 

Subparagraph  A.  Reference  to  your  telegram  253,  recommend 
filling  approximately  10  per  cent  all  shells  with  gases  as  given  below, 
but  that  filling  plants  and  gas  factories  be  made  capable  of  filling  a 
total  of  25  per  cent.  Unless  ordinary  name  is  given,  gases  are 
designated  by  numbers  in  chemical  code  War  Gas  investigations.  Of 
75  millimeter  shells  fill  1  per  cent  Vincennite,  4  per  cent  phosgene 
or  trichloromethyl  chloroformate,  2  per  cent  chloropicrin,  2^  per 
cent  mustard  gas,  Yz  per  cent  with  bromoaeetone  and  ^2  per  cent  with 
smoke  material.  According  to  French  75  millimeter  steel  shells  should 
not  be  filled  with  Vincennite  more  than  three  months  before  being 
iised.  No  trouble  with  other  gases  or  other  sized  shells  except  that 
bromoaeetone  must  be  in  glass  lined  shells.  Of  4.7  inch  shells  fill 
5  per  cent  with  phosgene  or  trichloromethyl  chloroformate,  2  per  cent 
with  chloropicrin,  2^/^  per  cent  with  mustard  gas,  Y2  per  cent 
with  bromoaeetone  and  V2  per  cent  with  smoke  material.  Provide  same 
percentage  for  all  other  shells  up  to  and  including  8  inch  caliber 
as  for  4.7  inch  shells.  4  inch  Stokes'  mortar  will  use  same  gases  and 
smoke  shells  and  in  addition  thermit.  8  inch  projector  bombs  will 
use  the  same  as  the  Stokes'  mortar  and  also  oil  to  break  into  flame 
on  bursting.  Cloud  gas  cylinders  will  be  filled  with  50  or  60  per  cent 
phosgene,  mixed  with  40  to  50  per  cent  chlorine,  or  phosgene  and  some 
other  gas.  Renew  recommendation  that  filling  plants  be  established 
in  France  to  provide  sudden  shifts  in  gas  warfare  of  all  kinds,  as 
well  as  for  filling  all  4  inch  Stokes'  mortar  bombs,  8  inch  projector 
bombs  and  cloud  gas  cylinders.  It  is  strongly  recommended  that 
efforts  be  made  to  produce  white  phosphorus  on  large  scale  for  its 
usefulness  both  as  smoke  screens  and  to  produce  casualties. 

Subparagraph  B.  For  the  Adjutant  General  of  the  Army.  With 
reference  to  paragraph  2,  my  cablegram  181,  desire  information  as 
to  whether  recommendation  is  approved  that  an  engineer  officer  assisted 
by  Professor  Hulett  be  assigned  to  Gas  Service  in  Washington  to 
handle  all  orders  and  correspondence  concerning  gas. 


10?  _ , ;  ;  .\  .  .^  CHEMICAL  WARFARE 

SubparagTaph  C.  For  Surgeon  General.  With 'reference  to  para- 
graph 2  your  cablegram  205,  and  paragraph  2,  my  cablegram  181, 
what  is  status  of  chemical  laboratory  for  France?  Also  have  the 
12  selected  Reserve  Officers  for  training  in  gas  defense  sailed  for 
France. 

Subparagraph  D.  With  reference  to  paragraph  17  your  cablegram 
165  and  paragraph  2  my  cablegram  181,  Tissot  has  constructed  simpler 
model  of  his  mask  for  attachment  to  any  box.  Have  ordered  6  which 
will  be  completed  in  two  weeks,  3  of  which  will  be  forwarded  at  once. 
A  simple  type  such  as  this  may  prove  useful  for  large  number  of 
troops.  Letter  of  permission  to  manufacture  Tissot  masks  being 
forwarded. 

Subparagraph  E.  With  reference  to  paragraph  8  your  cablegram 
143,  and  paragraph  4  your  cablegram  247,  in  considering  charcoal 
and  other  fillers  for  canister  of  box  respirator  it  should  be  remembered 
that  the  front  is  very  damp,  the  air  being  nearly  saturated  during 
greater  part  of  winter,  fall  and  spring. 

This  cable  is  given  in  full  to  show  that  not  later  than 
November  4,  1917,  it  was  known  in  the  United  States  not  only 
what  gases  would  be  required  but  also  in  what  shells,  bombs, 
guns  and  mortars  each  would  be  used.  While  a  small  quantity 
of  Vincennite  was  recommended  in  this  cable,  another  cable 
sent  within  a  month  requested  that  no  Vincennite  whatever 
be  manufactured.  This  decision  as  to  gases  and  guns  in  which 
they  were  to  be  used,  while  very  progressive,  proved  entirely 
sound  and  remained  unchanged,  with  slight  exceptions  due  to 
new  discoveries,  until  the  end  of  the  war.  Without  a  thorough 
understanding  of  tactics  a  proper  choice  of  gases  could  not 
have  been  made.  This  fact  emphasizes  the  necessity  of  having 
a  trained  technical  army  man  at  the  head  of  any  gas  service. 

Due  to  the  absence  of  a  Chemical  Warfare  Service  in  the 
United  States  at  this  time,  a  very  great  deal  of  the  information 
sent  from  France,  whether  by  cable  or  by  letter,  never  reached 
those  needing  it. 

Smoke.  About  the  first  of  December  after  a  study  of  results 
obtained  by  the  British  and  the  Germans  in  the  use  of  smoke 
in  artillery  shells  for  screening  purposes,  the  Gas  Service 
decided  that  much  more  smoke  than  had  been  stated  in  cable 
268  to  the  United  States  was  desirable.     The  General  Staff, 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE         103 

however,  refused  to  authorize  any  increase,  but  did  allow  to 
be  sent  in  a  cable  a  statement  to  the  effect  that  a  large  increase 
in  smoke  materials  might  be  advisable  for  smoke  screens,  and 
that  accordingly  the  amount  of  phosphorus  needed  in  a  year 
of  war  would  probably  be  three  or  four  times  the  one  and^  a 
lialf  million  pounds  of  white  phosphorus  stated  to  have  been 
contracted  for  by  the  Ordnance  Department  in  the  United 
States.  This  advanced  position  of  the  Gas  Service  in  regard 
to  smoke  proved  sound  in  1918,  when  every  effort  was  made 
to  increase  the  quantity  of  white  phosphorus  available  and  to 


Fig.  16 — Troops  Advancing  Behind  a  Smoke  Barrage  (Phosphorus). 

extend  its  use  in  artillery  shells  including  even  the  3  inch  Stokes' 
mortar. 

Overseas  Repair  Section  No.  1.  During  the  latter  part  of 
November,  1917,  Overseas  Repair.  Section  No.  1,  under  the 
command  of  Captain  Mayo-Smith,  Sanitary  Corps,  wi'th  four 
other  officers  and  130  men,  arrived  in  France.  Since  mask 
development  and  manufacture  in  the  United  States  was  still 
under  the  Medical  Department,  this  mask  repair  section  was 
organized  as  a  part  of  the  Sanitary  Corps.  As  there  were  at 
that  time  no  masks  to  be  repaired  and  no  laboratory  equip- 
ment or  buildings  for  that  purpose  on  hand  and  none  likely 
to  be  for  months  t6  come,  Captain  Mayo-Smith  was  assigned 
to  duty  under  Colonel  Crawford,  Chief  Gas  Officer  with  the 


104  CHEMICAL  WARFARE 

Line  of  Communication,  in  Paris.  A  site  for  a  mask  repair 
plant  was  located  at  Chateauroux,  and  a  site  for  a  gas  depot 
at  Gievres  was  investigated.  Inasmuch  as  there  was  at  that 
time  greater  need  for  men  to  learn  the  handling  of  poisonous 
gases  than  to  repair  masks,  some  40  or  50  of  the  company  were 
put  in  gas  shell  filling  plants  at  Aubervilliers  and  Vincennes 
in  the  suburbs  of  Paris,  while  later  still  others  were  assigned 
to  Pont  de  Claix  near  Grenoble.  The  remainder  of  the  company 
were  used  in  the  Gas  Depot  at  Gievres  and  in  the  office  in  Paris. 

It  was  not  until  the  latter  part  of  June,  1918,  that  the 
mask  repair  plant  began  operations.  In  the  meantime  these 
men  did  very  valuable  work  in  shell  filling  and  in  learning 
the  manufacture  of  gases.  Several  of  them  were  sent  to  the 
United  States,  some  of  them  remaining  throughout  the  war  to 
aid  in  gas  manufacture  and  in  shell  filling. 

Construction  Division,  Gas  Service.  The  Construction 
Division  under  Colonel  Crawford  in  Paris  made  complete  plans 
for  phosgene  manufacturing  plants,  for  shell  filling  plants  and 
for  the  Mask  Repair  Plant.  These  plans  included  a  complete 
layout  of  the  work  for  all  persons  to  be  employed  in  the  plants. 
During  this  same  time  a  very  careful  study  of  the  possibilities 
for  manufacturing  gas  for  filling  shell  in  France  was  made. 

Finally  about  March  1,  in  accordance  with  the  strong  recom- 
mendations of  these  men,  Fries  reported  to  General  Pershing  in 
person  that  the  manufacture  of  gas  as  well  as  the  filling  of  shell  in 
France  was  inadvisable  from  every  point  of  view  and  accordingly 
he  recommended  that  gas  manufacture  and  shell  filling  in  France 
be  given  up.  General  Pershing  strongly  approved  the  recom- 
mendation and  a  cablegram  was  at  once  sent  to  the  United  States 
to  that  effect.  The  main  risason  for  this  action  was  the  lack  of 
chlorine,  since  chlorine  was  the  principal  ingredient  of  nearly  all 
poisonous  gases  then  in  use.  Chlorine  takes,  besides  salt,  electric 
power  and  lots  of  it.  Electric  power  requires  coal  or  water  power. 
Neither  of  the  latter  sources  were  available  in  France.  This 
question  was  gone  into  very  thoroughly.  The  only  place  where 
power  might  have  been  developed  was  in  a  remote  spot  near 
Spain,  and  the  outlook  there  was  such  that  it  appeared  impos- 
sible to  begin  the  manufacture  of  chlorine  under  two  years. 
On  the  other  hand  the  shipment  of  chlorine  from  the  United 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE        105 

States  required  from  75  per  cent  to  100  per  cent  of  the  tonnage 
required  to  ship  the  manufactured  gases  themselves,  to  say 
nothing  of  the  labor,  raw  materials,  and  the  machinery  that 
would  have  had  to  be  shipped  in  order  to  manufacture  gas 
in  /France. 

\/ Mustard  Gas.  As  previously  stated  Mustard  Gas  was  first 
iised^by  the  Germans  against  the  British  at  Ypres  on  the  nights 
of  July  11  and  12,  1917.  It  was  not  used  much  against  the 
French  until  more  than  two  months  later.  Indeed,  gas  was 
never  used  by  the  Germans  to  the  same  extent  against  the 
French  as  against  the  English.  There  are  probably  two  reasons 
for  this ;  first,  the  Germans  had  a  deeper  hatred  for  the  British 
than  the  French;  second,  the  British  morale  was  higher  than 
the  French  in  1917,  and  the  German  thought  that  if  he  could 
break  down  this  British  morale,  he  could  win  the  war. 

The  first  attack  came  as  a  surprise  and  accordingly  got  an 
unusually  large  number  of  casualties.  As  previously  stated 
the  casualties  numbered  about  20,000  in  about  six  weeks.  This 
number  was  considered  so  serious  that  the  beginning  of  the 
series  of  attacks  against  Ypres  in  the  fall  of  1917,  was  delayed 
by  the  British  for  10  days  or  two  weeks  until  they  could  study 
better  how  to  avoid  such  great  losses  from  mustard  gas.  While 
tlie  composition  of  the  gas  was  known  within  two  or  three 
days,  as  well  as  the  laboratory  method  by  which  it  was  first 
manufactured  by  Victor  Meyer  in  1886,  it  took  some  11  months 
to  develop  reliable  and  practical  methods  of  manufacturing 
ii  on  a  large  scale.  The  Inter-allied  Gas  Conference  in  Sep- 
tember, 1917,  gave  a  great  deal  of  attention  to  mustard  gas 
and  methods  of  combating  it  both  from  the  view  point  of 
prevention  and  of  curing  those  gassed  by  it. 

Just  following  the  close  of  that  conference  a  cable  was 
sent  to  the  United  States  asking  the  possibility  of  manufac- 
turing ethylene  chlorhydrin,  the  principal  element  in  the  manu- 
facture of  mustard  gas  by  the  only  process  then  known. .  Later, 
that  is  about  the  middle  of  October,  a  cablegram  was  sent 
urging  investigation  into  the  manufacture  of  this  gas.  It  is 
believed  a  great  deal  of  time  might  have  been  saved  had  the 
policy  of  undue  secrecy  not  been  adopted  by  the  British  and 
others  before  the  Americans  entered  the  war.    In  fact  we  were 


106 


CHEMICAL  WARFARE 


only  told  in  whispers  the  formula  for  mustard  gas,  and  where 
a  description  of  it  could  be  found  in  German  chemistries.  This 
was  arrant  nonsense  since  if  the  Germans  had  gotten  all  mus- 
tard gas  information  then  in  the  hands  of  the  British  they 
\*^ould  have  received  far  less  information  than  they  already 
possessed  on  mustard  gas. 

Whether  the  information  sent  to  the  United  States  on 
mustard  gas  ultimately  proved  of  any  great  value  is  an  open 
question  since  the  methods  adopted  in  the  United  States  were 


PMjM 

Fig.  17.— ''Who  Said  G&sT 

very  greatly  superior  to  those  used  in  England  and  in  France. 
It  probably  helped  by  suggestion  rather  than  by  actual  details 
of  design.  Anyhow  it  all  emphasizes  the  difficulties  encountered 
in  war  when  so  vital  a  stibstance  as  mustard  gas  must  be 
investigated  after  the  enemy  has  begun  using  it  on  a  large 
scale. 

Delay  of  British  Masks.  As  December  1  approached,  and 
as  nothing  further  had  been  heard  of  the  order  for  300,000 
British  Respirators  placed  about  the  middle  of  October,  a 
telegram  was  sent  to  England  asking  if  deliveries  would  be 
made   as  required  in  the  order  for  the  masks.     This   order 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE         107 

required  the  first  75,000  to  be  delivered  December  1,  1917. 
In  reply  it  was  stated  that  the  British  could  not  fnrnish  these 
masks,  and  that  they  understood  that  the  Americans  were 
just  beginning  a  large  output  of  masks  in  the  United  States. 
An  exchange  of  cablegrams  with  the  United  States  showed 
that  no  masks  could  be  expected  from  there  for  3  to  5  months. 
Moreover  it  became  increasingly  evident  that  the  Americans 
were  going  into  the  battle  line  sooner  than  at  first  contemplated. 
Another  cablegram  was  then  sent  to  England  urging  the 
delivery  of  these  masks.  The  reply  was  to  the  effect  that  the 
English  Government  could  not  deliver  the  masks  because  they 
did  not  have  enough  for  their  own  use.  This  situation  was 
fcVery  serious.  Unless  the  order  for  300,000  masks  placed  with) 
the  British  could  be  filled,  we  were  facing  the  necessity  of 
sending  American  troops  into  the  front  line  with  only  the 
French  M-2  mask.  While  the  M-2  mask  was  then  the  only 
mask  used  by  the  French,  it  was  well  known  to  afford  prac- 
tically no  protection  against  the  high  concentrations  of  phos- 
gene obtained  from  cloud  or  projector  attacks.  And  it  was 
just  such  attacks  as  these  that  our  men  would  encounter  in 
the  front  line  during  training.  Accordingly  arrangements 
were  made  for  a  hurried  trip  to  England. 

Colonel  Harrison  of  the  British  Royal  Engineers  was  in 
charge  of  the  British  manufacture  of  masks  and  it  is  desired 
here  to  express  appreciation  of  his  uniform  courtesy  and  great 
helpfulness.  He  exhibited  their  methods  and  facilities  and 
assured  us  they  could  meet  any  requirements  of  ours  for  masks 
up  to  a  half  million,  or  even  more  if  necessary,  provided  they 
were  given  time  to  establish  additional  facilities.  Finally 
after  a  further  exchange  of  cables  the  masks  were  obtained. 
During  December,  1917  and  January,  1918,  when  every 
effort  was  being  made  to  hurry  a  lot  of  masks  from  Havre — • 
Havre  being  the  British  supply  base  in  France  from  which  the 
masks  were  issued  to  the  United  States,  the  severe  cold  and 
snow  had  so  disorganized  French  traffic  that  it  was  extremely 
difficult  to  get  cars  moving  at  all.  In  an  effort  to  get  the 
masks,  priority  of  shipment  was  obtained  and  two  or  three 
officers  were  assigned  to  convoy  the  cars.  Notwithstanding 
convoying,  one  carload  of  4,000  masks,  mainly  threes  and  fours, 


108  CHEMICAL  WARFARE 

became  lost  and  only  turned  up  ^Ye  weeks  later.  To  make 
matters  worse  the  British  were  sending  us  very  many  more 
of  the  small  sized  No.  2  masks  than  we  could  use.  The  loss 
of  this  carload  of  4,000  number  threes  and  fours  was  all  but 
a  tragedy.  Indeed,  in  order  to  get  the  First  Brigade  of  the 
First  Division  equipped  in  time  it  was  necessary  to  take  a 
large  number  of  masks  already  issued  to  men  of  the  Second 
Brigade.  These  masks  were  first  thoroughly  washed  and  dis- 
infected and  then  re-issued. 

This  all  emphasizes  the  great  difficulties  that  are  encountered 
when  a  new  and  vital  service  must  be  organized  in  war  4,000 
miles  overseas  without  material,  home  supplies,  or  men  to  draw 
from.  This  struggle  to  get  sufficient  masks  to  keep  all  men 
fully  equipped  remained  very  acute  until  in  July,  1918,  when 
the  arrival  of  hundreds  of  thousands  of  masks  from  the  United 
States  made  the  situation  entirely  safe.  Even  then  the  neces- 
sity of  w^eakening  the  elastics  and  shortening  the  rubber  tubing 
of  the  mouthpieces  on  some  700,000  masks,  doubled  up  our 
work  tremendously,  and  added  enormously  to  our  troubles  in 
getting  masks  to  the  front  in  time. 

Notwithstanding  these  troubles  the  Chemical  Warfare  Sup- 
ply Service  never  failed  and  finally  forged  to  the  very  fore- 
front of  all  American  supply  services.  Its  method  of  issuing 
supplies  to  troops  at  the  front  has  been  adopted  as  the  standard 
for  American  field  armies  of  the  future. 

Technical 

n\  Gas  Laboratory  in  Paris.  Early  in  January,  1918,  the  first 
members  of  the  Chemical  Service  Section,  National  Army, 
under  the  command  of  Colonel  R.  F.  Bacon,  arrived  in  France 
and  reported  for  duty.  Previously,  a  laboratory  site  at 
Puteaux,  a  suburb  of  Paris,  had  been  selected.  This  plant 
had  been  built  by  a  society  for  investigation  into  tuberculosis. 
Previous  to  the  arrival  of  the  Chemical  Service  Section, 
information  had  been  requested  from  the  United  States  by 
cable  as  to  the  size  of  the  laboratory  section  to  be  sent  over. 
The  reply  stated  that  the  number  would  probably  total  about 
100  commissioned  and  enlisted.  The  site  at  Puteaux  was 
accordingly  definitely  decided  upon.    Just  following  this  deci- 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE 


109 


sion  two  cables,  one  after  the  other,  came  from  the  United 
States  recommending  certain  specified  buildings  in  Paris  for 
the  laboratory.  It  was  found  upon  investigation  in  both  cases 
that  the  buildings  were  either  absolutely  unsuited  or  unfinished. 
This  was  another  case  of  trying  to  fight  a  war  over  4,000 
miles  of  cable.  Colonel  Bacon  was  made  head  of  the  Technical 
Division,  whicli  position  he  held  throughout  the  war. 


I 


Fig.  18. — Shaper  for  Opening  Captured  Gas  Shell.' 

Technically  Trained  Men.  In  January,  1918,  in  response 
to  a  cable  from  the  United  States  a  request  had  been  made 
on  the  French  Government  to  send  six  of  their  ablest  glass 
blowers  to  the  United  States  to  aid  in  making  glass  lined 
shells.  The  French  Gas  authorities  said  that  it  would  be  impos- 
sible to  send  those  or  indeed  any  other  men  trained  in  the 
manufacture  or  handling  of  poisonous  gases  or  gas  containers 
as  they  did  not  have  enough  such  men  for  their  own  work. 
Accordingly  a  cablegram  was  drafted  and  sent  to  the  United 
States,  requesting  that  50  men  experienced  in  various  lines 


no  CHEMICAL  WARFARE 

of  technical  and  chemical  work  be  sent  to  France.  The  French 
authorities  said  they  would  put  them  in  any  factories,  labora- 
tories or  experimental  places  that  the  Chief  of  the  Gas  Service 
desired.  A  second  inquiry  about  these  men  was  sent  but  never- 
theless no  answer  was  ever  received  and  no  men  were  sent. 

Protection  Against  Particulate  Clouds.  Just  at  this  time, 
about  the  first  of  February,  1918,  the  danger  that  the  Germans 
might  devise  some  better  method  of  sending  over  diphenyl- 
chloroarsine  than  by  pulverizing  it  in  high  explosive  shell  was 
felt  to  be  serious.  The  British  had  just  then  perfected  protec- 
tion against  diphenylchoroarsine  by  employing  unsized  sulfate 
wood  pulp  paper— 48  to  60  layers  being  required.  This  number 
of  layers  was  found  to  be  necessary  as  they  are  very  thin  and 
porous.  The  British  had  developed  a  method  of  putting  this 
paper  around  a  canister  and  yet  keeping  the  canister  small 
enough  to  fit  into  the  knapsack  by  reversing  its  position  therein ; 
that  is,  putting  the  canister  in  the  compartment  of  the  knapsack 
made  for  the  face  piece  and  putting  the  face  piece  in  the 
other  compartment.  Some  of  our  own  officers  and  enlisted  men 
were  sent  to  England  to  work  with  the  British  on  this  and 
an  order  given  them  for  200,000  of  the  protected  canisters. 
They  improved  on  the  methods  of  the  British  and  as  it  was 
found  that  sulfate  paper  was  very  scarce,  investigations  were 
made  to  see  if  any  of  it  could  be  manufactured  in  France.  Very 
soon  thereafter  such  a  place  was  located  near  the  city  of  Nancy. 
Following  this  a  cablegram  was  sent  to  the  United  States 
giving  complete  specifications  for  making  this  diphenylchloro- 
arsine  protection.  From  this  cablegram  successful  samples 
were  made  though  somewhat  more  bulky  than  those  developed 
in  England.  Very  few,  however,  of  these  were  made  in  the 
United  States  due,  we  were  informed,  to  the  poor  quality  of 
the  sulfate  paper.  Work  was  however  begun  energetically  in 
the  United  States  on  other  methods  of  protection  against 
diphenylchlor  oar  sine. 

Numbers  of  Chemists  Needed.  It  was  figured  that  out  of 
a  total  force  of  some  1,400  gas  officers  there  would  be  needed 
in  the  A.  E.  F.,  exclusive  of  those  in  regiments,  approximately 
200  chemists,  i.e.,  about  15  per  cent  of  the  whole.  "We  arranged 
to  have  a  good  chemist  on  each  Division,  Corps  and  Army 


> 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE         111 

►Staff,  and  a  certain  number  with  the  gas  troops.  It  was  pro- 
posed to  put  20  to  40  in  the  laboratory  in  Paris  and  not  to 
exceed  20  at  the  experimental  field.  This  subject  of  personnel 
is  touched  on  for  the  reason  that  a  few  people  seem  to  have 
the  idea  that  the  Chemical  Warfare  Service  should  be  made 
up  of  chemists  exclusively.  This  is  very  far  from  being  true. 
It  was  and  is  believed  that  the  Chemical  Warfare  Service 
sliould  be  composed  of  men  from  every  walk  of  life.  In  three 
positions  out  of  every  four  in  the  field  a  good  personality  com- 
bined with  energy,  hard  work  and  common-sense  count  for 
more  than  mere  technical  training. 

Hanlon  (Experimental)  Field.  As  early  as  December  15, 
917,  it  was  decided  that  an  experimental  field  in  France  was 
ut'cessary,  and  a  letter  was  written  to  the  General  Staff  request- 
ing authority  to  establish  one.  After  considerable  delay  the 
authority  was  granted  and  search  for  a  site  begun.  This  was 
no  easy  task.  While  the  French  were  loading  millions  of  gas 
shells  at  the  edge  of  Paris,  they  appeared  unwilling  at  first 
to  have  us  establish  a  gas  experimental  field  except  in  aban- 
doned or  inaccessible  spots.  Finally  a  very  good  site  was 
found  and  agreed  to  by  the  French  some  7  miles  south 
of  General  Headquarters.  Just  when  we  were  ready  to  start 
work  the  French  discovered  that  the  proposed  field  included 
a  portion  of  one  of  their  artillery  firing  ranges.  They  then 
suggested  another  site  within  3  miles  of  General  Head- 
quarters. This  was  a  rather  fortunate  accident  as  the  site 
suggested  was  a  better  one  than  at  first  picked  out.  The  field 
was  roughly  rectangular  from  7  to  8  miles  in  length,  and 
3  to  4  miles  in  width.  The  total  area  was  about  20  square  miles. 
The  work  of  this  experimental  field  proved  a  great  success 
and  was  rapidly  becoming  the  real  center  of  the  Gas  Service 
in  France. 

The  old  saying  that  the  history  of  a  happy  country  is  very 
brief  applies  to  this  story  of  the  Technical  Section  of  the  Gas 
Service  in  France.  Its  work  did  not  begin  as  early  as  that 
of  the  other  sections,  and  as  considerable  of  it  was  of  a  nature 
that  could  be  put  off  without  immediate  fatal  effects,  the 
Section  was  enabled  to  grow  without  the  very  serious  draw- 
backs encountered  by  other  Sections  of  the  Gas  Service. 


il2  CHEMICAL  WARFARE 

Nevertheless  its  usefulness  was  very  great.  Those  of  the 
Technical  Section  either  at  the  experimental  field  or  at  the 
laboratory  were  charged  with  the  opening  of  all  sorts  of  known 
and  unknown  gas  and  high  explosive  shells,  fuses  and  similar 
things  to  determine  their  contents  and  their  poisonous  or 
explosive  qualities.  This  was  work  of  a  very  technical  nature, 
and  at  the  same  time  highly  dangerous. 

As  stated  elsewhere,  the  determination  of  the  life  of  the 
masks  became  one  of  the  problems  which  the  laboratory  was 
trying  to  solve.  Hundreds  of  canisters  were  tested,  and 
hundreds  per  month  would  have  continued  to  have  been  tested 
throughout  the  remainder  of  the  war  had  the  war  gone  into 
1919.  It  was  on  the  Technical  Section  that  devolved  the  duty 
of  determining  at  the  earliest  possible  moment  the  physical 
properties  as  well  as  the  physiological  effects  of  any  new  gas. 

Also  on  that  Section  fell  the  preliminary  reports  as  to  the 
probable  usefulness  in  war  of  a  new  gas  whether  sent  over 
by  the  enemy  or  suggested  by  our  own  Technical  men,  or  those 
of  our  Allies.  This  was  indeed  a  task  by  itself,  as  it  required 
a  wide  knowledge' of  the  methods  of  using  gases,  methods  of 
manufacturing  them,  and  methods  of  projecting  them  on  the 
field  of  battle. 

In  addition,  it  was  the  duty  of  the  Technical  Section  to 
keep  the  Chief  of  the  Service  fully  informed  on  all  the  latest 
developments  in  gases  and  to  get  that  information  in  shape 
so  that  the  Chief  with  his  increasingly  wide  range  of  duties 
would  be  enabled  to  keep  track  of  them  without  reading  the 
enormous  amount  ordinarily  written. 

A  much  earlier  start  on  technical  work  would  have  proved 
of  immense  advantage.  In  case  of  another  war,  the  technical 
side  of  chemical  warfare  should  be  taken  up  with  the  very 
first  expedition  that  proceeds  to  the  hostile  zone.  Had  that 
been  done  in  France,  we  would  have  had  masks  and  gases  and 
proper  shells  and  bombs  at  least  six  months  before  we  did. 

Intelligence 

While  Intelligence  was  for  a  long  time  under  the  Training 
or  Technical  Divisions,  it  finally  assumed  such  importance  that 
it  was  made  a  separate  Division.     It  was  so  thoroughly  organ- 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE         113 

ized  that  by  the  time  of  the  Armistice  the  Chief  of  the  Division 
could  go  anywhere  among  the  United  States  forces  down  to 
companies  and  immediately  locate  the  Gas  Intelligence  officer. 

Intelligence  Division.  This  work  was  started  by  Lieutenant 
Colonel  Goss  within  a  month  after  he  reported  in  October, 
1917.  The  Intelligence  Division  developed  the  publication  of 
numerous  ocasional  pamphlets  and  also  a  weekly  gas  bulletin. 
So  extensive  was  the  work  of  this  Division  that  three  mimeo- 
graph machines  were  kept  constantly  going.  The  weekly  bul- 
letin received  very  flattering  notice  from  the  British  Assistant 
Chief  of  Gas  Service  in  the  Field.  He  stated  that  it  contained 
a  great  deal  of  information  he  was  unable  to  get  from  any 
other  source. 

Among  other  work  undertaken  by  this  Intelligence  Division 
was  the  compilation  of  a  History  of  the  Chemical  Warfare 
Service  in  France.  This  alone  involved  a  lot  of  work.  In 
order  that  this  history  might  be  truly  representative,  about 
three  months  before  the  Armistice  both  moving  and  still  pic- 
tures were  taken  of  actual  battle  conditions,  as  well  as  of 
numerous  works  along  the  Service  of  Supplies. 

Without  going  into  further  detail  it  is  sufficient  to  say  that 
when  the  Armistice  was  signed  there  were  available  some  200 
still  pictures,  and  some  8,000  feet  of  moving  picture  films. 
Steps  were  immediately  taken  to  have  this  work  continued 
along  definite  lines  to  give  a  complete  and  continuous  history 
of  the  Chemical  Warfare  Service  in  France  in  all  its  phases. 

The  intelligence  work  of  the  Gas  Service,  while  parallel 
to  a  small  extent  with  the  General  Intelligence  Service  of  the 
A.  E.  F.,  had  to  spread  to  a  far  greater  extent  in  order  to 
get  the  technical  details  of  research,  manufacture,  develop- 
ment, proving,  and  handling  poisonous  gases  in  the  field.  It 
included  also  obtaining  information  at  the  seats  of  Government 
of  the  Allies,  as  well  as  from  the  enemy  and  other  foreign 
sources. 

The  most  conspicuous  intelligence  work  done  along  these 

lines  was  by  Lieutenant  Colonel  J.  E.  Zanetti,  who  was  made 

Chemical  Warfare  liaison  officer  with  the  French  in  October, 

1917.    He  gathered  together  and  forwarded  through  the  Head- 

uarters  of  the  Chemical  Warfare  Service  to  the  United  States 


1 14  CHEMICAL  WARFARE 

more  information  concerning  foreign  gases,  and  foreign  methods 
of  manufacturing  and  handling  them,  than  was  sent  from  all  other 
sources  combined.  By  his  personality,  energy  and  industry  he 
obtained  the  complete  confidence  of  the  French  and  British.  This 
confidence  was  of  the  utmost  importance  in  enabling  him  to  get 
information  which  could  have  been  obtained  in  no  other  way. 
Suffice  to  say  that  in  the  13  months  he  was  liaison  officer  with 
the  French  during  the  war,  he  prepared  over  750  reports,  some 
of  them  very  technical  and  of  great  length. 

As  a  whole,  the  Intelligence  Division  was  one  of  the  most 
successful  parts  of  the  Chemical  Warfare  Service.  Starting  2V2 
years  after  the  British  and  French,  the  weekly  bulletin  and  occa- 
sional papers  sent  out  by  'the  Chemical  Warfare  Service  on 
chemical  warfare  matters  came  to  be  looked  upon  as  the  best 
available  source  for  chemical  warfare  information,  not  alone  by 
our  own  troops  but  also  by  the  British. 

Medical 

The  Medical  Section  of  the  Chemical  Warfare  Service  was 
composed  of  officers  of  the  Medical  Department  of  the  Army 
attached  to  the  Chemical  Warfare  Service.  These  were  in 
addition  to  others  who  worked  as  an  integral  part  of  the 
Chemical  Warfare  Service,  either  at  the  laboratory  or  on  the 
experimental  field  in  carrying  out  experiments  on  animals  to 
determine  the  effectiveness  of  the  gases. 

The  Medical  Section  was  important  for  the  reason  that  it 
formed  the  connecting  link  betAveen  the  Chemical  Warfare 
Service  and  the  Medical  Department.  Through  this  Section, 
the  Medical  Department  was  enabled  to  know  the .  kinds  of 
gases  that  would  probably  be  handled,  both  by  our  own  troops 
and  by  the  enemy,  and  their  probable  physiological  effects. 

Colonel  H.  L.  Gilchrist,  Medical  Department,  was  the  head 
of  this  Section.  It  was  through  his  efforts  that  the  Medical 
Department  realized  in  time  the  size  of  the  problem  that  it 
had  to  encounter  in  caring  for  gas  patients.  Indeed,  records 
of  the  war  showed  that  out  of  224,089  men,  exclusive  of 
Marines,  admitted  to  the  hospitals  in  France,  70,552  were  suf- 
fering from  gas  alone.     These  men  received  a  total  of  266,112 


THE  CHEMICAL  WARFARE  SERVICE  IN  FRANCE         115 

wounds,  of  which  88,980,  or  33.4  per  cent,  were  gas.  Thus 
^/a  of  all  wounds  received  by  men  admitted  to  the  hospital 
were  gas.  "While  the  records  show  that  the  gas  cases  did  not 
remain  on  the  average  in  the  liospitals  quite  as  long  as  in  the 
case  of  other  classes  of  wounds,  yet  gas  cases  became  one  of 
the  most  important  features  of  the  Medical  Department 's  work 
in  the  field. 

The  Medical  Section,  through  its  intimate  knowledge  of 
what  was  going  on  in  the  Chemical  Warfare  Service  as  well 
as  what  was  contemplated  and  being  experimented  with,  was 
enabled  to  work  out  methods  of  handling  all  gas  cases  far 
in  advance  of  what  could  have  been  done  had  there  been  no 
such  section.  One  instance  alone  illustrates  this  fully.  It 
became  known  fairly  early  that  if  a  man  who  had  been  gassed 
with  mustard  gas  could  get  a  thorough  cleansing  and  an  entire 
change  of  clothing  within  an  hour  after  exposure,  the  body 
burns  could  be  eliminated  or  largely  decreased  in  severity. 
This  led  to  the  development  of  degassing  units.  These  con- 
sisted of  1,200  gallon  tanks  on  five-ton  trucks  equipped  with 
a  heater.  Accompanying  this  were  sprinkling  arrangements 
whereby  a  man  could  be  given  a  shower  bath,  his  nose,  eyes  and 
ears  treated  with  bicarbonate  of  soda,  and  then  be  given  an 
entire  change  of  clothing.  These  proved  a  very  great  success, 
although  they  were  not  developed  in  time  to  be  used  exten- 
sively before  the  war  closed. 

There  is  an  important  side  to  the  Medical  Section  during 
peace,  that  must  be  kept  in  mind.  The  final  decision  as  to 
whether  a  gas  should  be  manufactured  on  a  large  scale  and 
used  extensively  on  the  field  of  battle  depends  upon  its 
physiological  and  morale  effect  upon  troops.  In  the  case  of 
the  most  powerful  gases,  the  determination  of  the  relative 
values  of  those  gases  so  far  as  their  effects  on  human  beings 
is  concerned  is  a  very  laborious  and  exacting  job.  Such  gases 
have  to  be  handled  with  extreme  caution,  necessitating  many 
experiments  over  long  periods  of  time  in  order  to  arrive  at 
.correct  decisions. 


CHAPTER   V 
CHLORINE 

Chlorine  is  of  interest  in  chemical  warfare,  not  only  because 
it  was  the  first  poison  gas  used  by  the  Germans,  but  also 
because  of  its  extensive  use  in  the  preparation  of  other  war 
gases.  The  fact  that,  when  Germany  decided  upon  her  gas 
program,  her  chemists  selected  chlorine  as  the  first  substance 
to  be  used,  was  the  direct  result  of  an  analysis  of  the  require- 
ments of  a  poison  gas. 

To  be  of  value  for  this  purpose,  a  chemical  must  satisfy 
at  least  the  following  conditions: 

( 1 )  It  must  be  highly  toxic. 

(2)  It  must  be  readily  manufactured  in  large  quantities. 

(3)  It  must  be  readily  compressible  to  a  liquid  and  yet  be 
more  or  less  easily  volatilized  when  the  pressure  is  released. 

(4)  It  should  have  a  considerably  higher  density  than  that  of 
air. 

(5)  It  should  be  stable  against  moisture  and  other  chemicals. 

Considering  the  properties  of  chlorine  in  the  light  of  these 
requirements,  we  find: 

(la)  Chlorine  is  fairly  toxic,  though  its  lethal  concentration 
(2.5  milligrams  per  liter  of  air)  is  very  high  when  compared  with 
some  of  the  later  gases  developed.  This  figure  is  the  concentra- 
tion necessary  to  kill  a  dog  after  an  exposure  of  thirty  minutes^ 
Its  effects  during  the  first  gas  attack  showed  that,  with  no 
protection,  the  gas  was  very  effective. 

(2a)  Chlorine  is  very  readily  manufactured  by  the  elec- 
trolysis of  a  salt  (sodium  chloride)  solution.  The  operation  is 
described  below.     In  100-pound  cylinders,  the  commercial  prod- 

116 


CHLORINE  117 

net  sold  before  the  War  for  5  cents  a  pound.  Therefore  on  a 
large  scale,  it  can  be  manufactured  at  a  very  much  smaller  figure. 

(3a)  Chlorine  is  easily  liquefied  at  the  ordinary  temperature 
by  compression,  a  pressure  of  16.5  atmospheres  being  required  at 
18°  C.  The  liquid  which  is  formed  boils  at  —33.6°  C.  at  ordinary 
atmospheric  pressure,  so  that  it  readily  vaporizes  upon  opening 
the  valve  of  the  containing  cylinder.  Such  rapid  evaporation 
inside  would  cause  a  considerable  cooling  of  the  cylinder,  but 
this  is  overcome  by  running  the  outlet  pipe  to  the  bottom  of  the 
tank,  so  that  evaporation  takes  place  at  the  end  of  the  outlet  pipe. 

(4a)  Chlorine  is  2.5  times  as  heavy  as  air,  and  therefore  the 
gas  is  capable  of  traveling  over  a  considerable  distance  before  it 
dissipates  into  the  atmosphere. 

(Set)  The  only  point  in  which  chlorine  does  not  seem  to  be  an 
ideal  gas,  is  in  the  fact  that  it  is  a  reactive  substance.  This  is  best 
seen  in  the  success  of  the  primitive  protection  adopted  by  both 
the  British  and  the  French  during  the  days  immediately  follow- 
ing the  first  gas  attack. 

At  first,  however,  chlorine  proved  a  very  effective  weapon. 
During  the  first  six  months  of  its  use,  its  value  was  maintained 
by  devising  new  methods  of  attack.  When  these  were 
exhausted,  phosgene  was  added  (see  next  chapter).  With 
the  decline  in  importance  of  cloud  gas  attacks,  and  the  develop- 
ment of  more  deadly  gases,  chlorine  was  all  but  discarded  as  a 
true  war  gas,  but  remained  as  a  highly  important  ingredient 
in  the  manufacture  of  other  toxic  gases. 

Manufacture  in  the  United  States 

It  was  at  first  thought  that  the  existing  plants  might  be  able  to 
supply  the  government  *s  need  of  chlorine.  The  pre-war  production 
averaged  about  450  tons  (900,000  pounds)  per  day.  The  greater 
amount  of  this  was  used  in  the  preparation  of  bleach,  only 
about  60,000  pounds  per  day  being  liquefied.  Only  a  few  of  the 
plants  were  capable  of  even  limited  expansion.  In  an  attempt 
to  conserve  the  supply,  the  paper  mills  agreed  to  use  only 
half  as  much  bleach  during  the  war,  which  arrangement  added 
considerably  to  the  supply  available  for  war  purposes.    It  was 


118 


CHEMICAL  WARFARE 


soon  recognized  that  even  with  these  accessions,  large  addi- 
tions would  have  to  be  made  to  the  chlorine  output  of  the 
country  in  order  to  meet  the  proposed  toxic  gas  requirements. 
After  a  careful  consideration  of  all  the  factors,  the  most 
important  of  which  was  the  question  of  electrical  energy,  it 
was  decided  to  build  a  chlorine  plant  at  Edgewood  Arsenal, 
with  a  capacity  of  100  tons  (200,000  pounds)  per  day.  The 
Nelson  cell  was  selected  for  use  in  the  proposed  plant.  During 
the   process   of  erection  of  the   plant,   the    Warner-Klipstein 


^fMdl;i  _.  1  1,^ 

^^^..^      ,,; 

\,~^      ■•  ^^''^'1|^,  i 

^mt^S^K/KM 

i .  _ 

H1M«S^B(^~ .  --ikbi^^i  f j«i^i«^^^ 

Fig.  19. — Chlorine  Plant,  Edgewood  Arsenal. 

Chemical  Company,  which  was  operating  the  Nelson  cell  in  its 
plant  in  Charleston,  West  Virginia,  agreed  that  men  might 
be  sent  to  their  plant  to  acquire  the  special  knowledge  required 
for  operating  such  a  plant.  Thus  when  the  plant  was  ready 
for  operation,  trained  men  were  at  once  available. 

The  following  description  of  the  plant  is  taken  from  an 
article  by  S.  M.  Green  in  Chemical  arid  Metallurgical  Engineer- 
ing for  July  1,  1919 : 


"The  chlorine  plant  building,   a  ground  plan  of  which   is  shown 
in  Figure  20,  consisted  of  a  salt  storage  and  treating  building,  two 


CHLORINE' 


119 


120  CHEMICAL  WARFARE 

cell  buildings,  a  rotary  converter  building,  etc.  In  connection  with 
the  chlorine  plant,  there  was  also  constructed  a  liquefying  plant  for 
chlorine  and  a  sulfur  chloride  manufacturing  and  distilling  plant. 

"The  salt  storage  and  treating  building  was  located  on  ground 
much  below  the  cell  buildings,  which  allowed  the  railroad  to  enter 
the  brine  building  on  the  top  of  the  salt  storage  tanks.  These  tanks 
were  constructed  of  concrete.  There  were  seven  of  these  tanks,  34  feet 
long,  28  feet  wide  and  20  feet  deep  having  a  capacity  for  storing  4,000 
tons  of  salt.  There  would  have  been  200  tons  of  salt  used  per  day 
when  the  plant  was  running  at  full  capacity. 

"On  the  bottom  of  each  tank  distributing  pipes  for  dissolving-water 
supply  were  installed,  and  at  the  top  of  each,  at  the  end  next  to 
the  building,  there  was  an  overflow  trough  and  skimmer  board  arranged 
so  that  the  dissolving- water  after  flowing  up  through  the  salt,  over- 
flowed into  this  trough  and  then  into  a  piping  system  and  into  either 
of  two  collecting  tanks.  The  system  was  so  arranged  that,  if  the  brine 
was  not  fully  saturated,  it  could  be  passed  through  another  storage 
tank  containmg  a  deep  body  of  salt.  The  saturated  brine  was  pumped 
from  the  collecting  tanks  to  any  one  of  24  treating  tanks,  each  of 
which  had  a  capacity  of  72,000  gallons. 

"The  eighth  storage  bin  was  used  for  the  storage  of  soda  ash, 
used  in  treating  the  saturated  brine.  This  was  deli\ered  from  the 
bin  on  the  floor  level  of  the  salt"  building  to  the  soda  ash  dissolving 
tanks.  From  these  tanks  it  was  pumped  to  any  one  of  the  24  treating 
tanks.  After  the  brine  was  treated  and  settled,  the  clear  saturated 
brine  was  drawn  from  the  treating  tanks  through  decanting  pipes  and 
delivered  by  pumps  to  any  one  of  the  four  neutralizing  tanks.  These 
were  located  next  to  a  platform  on  the  level  of  the  car  body.  This 
was  to  provide  easy  handling  of  the  hydrochloric  acid,  which  was 
purchased  at  first,  though  later  prepared  at  the  plant  from  chlorine 
and  hydrogen.  The  neutralized  brine  Avas  delivered  from  the  tanks 
by  a  pump  to  a  tank  located  at  a  height  above  the  floor  so  that  the 
brine  would  flow  by  gravity  to  the  cells  in  the  cell  building. 

"There  were  to  be  two  cell  buildings,  each  541  feet  long  by  82 
feet  wide,  and  separated  by  partitions  into  four  sections,  containing 
six  cell  circuits  of  74  cell  units.  Each  section  is  a  complete  unit  in 
itself,  provided  with  separate  gas  pump,  drying  and  cooling  equipment, 
and  has  a  guaranteed  capacity  of  12.5  tons  of  chlorine  gas  per  24 
hours. 

"Each  Nelson  electrolytic  cell  unit  consists  of  a  complete  fabricated 
steel  tank  13  by  32  by  80  inches,  a  perforated  steel  diaphragm  spot 
welded  to  supporting  angle  irons,  plate  glass  dome,  fourteen  Acheson 


CHLORINE  121 

gTaphite  electrodes  2.5  inches  in  diameter,  12  inches  long  and  fourteen 
pieces  of  graphite  4  by  4  by  17  inches,  and  various  accessories.  (The 
cell  is  completely  described  in  Chemical  and  Metallurgical  Engineering, 
August  1st,  1919.)  Each  cell  is  operated  by  a  current  of  340  amperes 
and  3.8  volts  and  is  guaranteed  to  produce  60  pounds  of  chlorine 
gas  and  65  pounds  of  caustic  soda  using  not  more  than  120  pounds 
of  salt  per  24  hours,  the  gas  to  be  at  least  95  per  cent  pure. 


Fig.  21. — Interior  View  of  the  Cell  Building. 

r  "The  salt  solution  from  the  cell  feed  tank,  located  in  the  salt 
treating  building,  flows  by  gravity  through  a  piping  system  located 
in  a  trench  running  the  length  of  each  cell  building,  and  is  delivered 
to  each  cell  unit  through  an  automatic  feeding  device  which  maintains 
a  constant  liquor  level  in  the  cathode  compartment. 

"The  remaining  solution  percolates  from  the  cathode  compartment 
through  the  asbestos  diaphragm  into  the  anode  compartment  and  flows 
from  the  end  of  the  cell,  containing  from  8  to  12  per  cent  caustic  soda, 
admixed  with  14  to  16  per  cent  salt,  into  an  open  trough  and  into 
a  pipe  in  the  trench  and  through  this  pipe  by  gravity  to  the  weak 
caustic  storage  tanks  located  near  the  caustic  evaporator  building. 


122 


CHEMICAL  WARFARE 


CHLORINE  123 

"The  gas  piping  from  the  individual  cell  units  to  and  including 
the  drying  equipment  is  of  chemical  stoneware.  The  piping  is  so 
designed  that  the  gas  can  be  drawn  from  the  cells  through  the  drying 
equipment  at  as  near  atmospheric  pressure  as  possible  in  order  that 
the  gas  can  be  kept  nearly  free  of  air.  When  operating,  the  suction 
at  the  pump  was  kept  at  1/20  inch  or  less.  The  quality  of  the  gas 
was  maintained  at  a  purity  of  98.5  to  99  per  cent.  The  coolers  used 
were  very  effective,  the  gas  being  cooled  to  within  one  degree  of  the 
temperature  of  the  cooling  water,  no  refrigeration  being  necessary. 
The  drjang  apparatus  consisted  of  a  stoneware  tower  of  special  design 
containing  a  large  number  of  plates,  and  thus  giving  a  very  large 
acid  exposure.  There  was  practically  no  loss  of  vacuum  through  the 
drying  tower  and  cooler.  The  gas  pumping  equipment  consisted  of 
two  hydroturbine  pumps  using  sulfuric  acid  as  the  compressing  medium. 
The  acid  was  cooled  by  circulation  through  a  double  pipe  cooler 
similar  to  those  used  in  refrigerating  work.  The  gas  was  delivered 
under  about  five  pounds  pressure  into  large  receiving  tanks  located 
just  outside  the  pump  rooms,  and  from  these  tanks  into  steel  pipe 
mains  which  conducted  the  gas  to  the  chemical  plant." 

The  purity  of  the  gas  was  such  that  it  was  not  found 
necessary  to  liquefy  it  for  the  preparation  of  phosgene. 


k 


Properties 


Chlorine,  at  ordinary  atmospheric  pressure  and  temper- 
vature,  is  a  greenish  yellow  gas  (giving  rise  to  its  name), 
which  has  a  very  irritating  effect  upon  the  membranes  of  the 
nose  and  throat.  As  mentioned  above,  at  a  pressure  of  16.5 
atmospheres  at  18°  C,  chlorine  is  condensed  to  a  liquid.  If 
the  gas  is  first  cooled  to  0°,  the  pressure  required  for  con- 
densation is  decreased  to  3.7  atmospheres.  This  yellow  liquid 
has  a  boiling  point  of  —33.6°  C.  at  the  ordinary  pressure.  If  very 
strongly  cooled,  chlorine  will  form  a  pale  yellow  solid  (at 
—102°  C.) .  Chlorine  is  2.5  times  as  heavy  as  air,  one  liter  weighing 
3.22  grams.  215  volumes  of  chlorine  gas  will  dissolve  in  100 
volumes  of  water  at  20°.  It  is  very  slightly  soluble  in  hot 
water  or  in  a  concentrated  solution  of  salt. 

Chlorine  is  a  very  reactive  substance  and  is  found  in  com- 
bination in  a  large  number  of  compounds.     Among  the  many 


124  CHEMICAL  WARFARE 

reactions  which  have  proved  important  from  the  standpoint 
of  chemical  warfare,  the  following  may  be  mentioned : 

Chlorine  reacts  with  '*hypo"  (sodium  thiosulfate)  with  the 
formation  of  sodium  chloride.  Hypo  is  able  to  transform  a 
large  amount  of  chlorine,  so  that  it  proved  a  very  satisfactory 
impregnating  agent  for  the  early  cloth  masks. 

Water  reacts  with  chlorine  under  certain  conditions  to 
form  hypochlorous  acid,  HOCl.  In  the  presence  of  ethylene, 
this  forms  ethylene  chlorhydrin,  which  was  the  basis  for  the 
first  method  of  preparing  mustard  gas.  In  the  later  method, 
in  which  sulfur  chloride  was  used,  chlorine  was  used  in  the  man- 
ufacture of  the  chloride. 

Chlorine  reacts  with  carbon  monoxide,  in  the  sunlight,  or 
in  the  presence  of  a  catalyst,  to  form  phosgene,  which  is  one 
of  the  most  valuable  of  the  toxic  gases. 

Chlorine  and  acetone  react  to  form  chloroacetone,  one  of 
the  early  lachrymators.  The  reaction  of  chlorine  with  toluene 
forms  benzyl  chloride,  an  intermediate  in  the  preparation  of 
bromobenzylcyanide. 

In  a  similar  way,  it  is  found  that  the  greater  number  of 
toxic  gases  use  chlorine  in  one  phase  or  another  of  their  prepa- 
ration. One  author  has  estimated  that  95  per  cent  of  all  the 
gases  used  may  be  made  directly  or  indirectly  by  the  use  of 
chlorine. 

Chlorine  has  been  used  in  connection  with  ammonia  and 
water  vapor  for  the  production  of  smoke  clouds.  The 
ammonium  chloride  cloud  thus  produced  is  one  of  the  best 
for  screening  purposes.  In  combination  witli  silicon  or  titanium 
as  the  tetrachloride  it  has  also  been  used  extensively  for  the  same 
purpose. 

On  the  other  hand  one  may  feel  that,  whatever  bad  reputa- 
tion chlorine  may  have  incurred  as  a  poison  gas,  it  has  made 
up  for  it  through  the  beneficial  applications  to  which  it  has 
lent  itself.  Among  these  we  may  mention  the  sterilization  of 
water  and  of  wounds. 

In  war,  where  stationary  conditions  prevail  only  in  a  small 
number  of  cases,  the  use  of  liquid  chlorine  for  sterilization  of 
water  is  impractical.  To  meet  this  condition,  an  ampoule 
filled  with,  chlorine  water  of  medium  concentration  has  been 


CHLORINE 


125 


developed,  which  furnishes  a  good  portable  form  of  chlorine 
as  a  sterilizing  agent  for  relatively  small  quantities  of  water. 
Chlorine  has  also  been  applied,  in  the  form  of  hypochlorite, 
to  the  sterilization  of  infected  wounds.  The  preparation  of 
the  solution  and  the  technique  of  the  operation  were  worked 
out  by  Dakin  and  Carrel.  This  innovation  in  war  surgery 
has  decreased  enormously  the  percentage  of  deaths  from 
infected  wounds. 


CHAPTER   VI 
PHOSGENE 

The  first  cloud  attack,  in  which  pure  chlorine  was  used, 
was  very  effective,  but  only  because  the  troops  attacked  with 
^it  were  entirely  unprotected.  Later,  in  spite  of  the  varied 
methods  of  attack,  the  results  were  less  and  less  promising, 
due  to  the  increased  protection  of  the  men  and  also  to  the 
gas  discipline  which  was  gradually  being  developed.  During 
this  time  the  Allies  had  started  their  gas  attacks  (Sept.,  1915), 
and  it  soon  became  evident  that,  if  Germany  was  to  keep  her 
supremacy  in  gas  warfare,  new  gases  or  new  tactics  would 
have  to  be  introduced. 

The  second  poison  gas  was  used  in  December,  1915,  when 
about  20-25  per  cent  of  phosgene  was  mixed  with  the  chlorine. 
Here  again  the  Germans  made  use  of  an  industry  already 
established.  Phosgene  is  used  commercially  in  the  preparation 
of  certain  dyestuffs,  especially  methyl  violet,  and  was  manu- 
factured before  and  during  the  war  by  the  Bayer  Company 
and  the  Badische  Anilin  und  Soda  Fabrik. 

Phosgene  can  not  be  used  alone  in  gas  cylinders  because 
of  its  high  boiling  point  (8°  C).  "While  this  is  considerably 
below  ordinary  temperatures,  especially  during  the  summer 
months,  the  rate  of  evaporation  is  so  slow  that  a  cloud  attack 
could  never  be  made  with  it  alone.  However,  when  a  mixture 
of  25  per  cent  phosgene  and  75  per  cent  chlorine,  or  50  per  cent 
phosgene  and  50  per  cent  chlorine  is  used  in  warm  weather 
there  is  no  difficulty  in  carrying  out  gas  attacks  from  cylinders. 
At  the  same  time  the  percentage  of  phosgene  in  the  mixture  is 
sufficiently  high  to  secure  the  advantages  which  it  possesses. 
These  advantages  are  at  least  three : 

(a)  Phosgene  is  more  toxic  than  chlorine.  It  requires 
2.5  milligrams  per  liter  of  chlorine  to  kill  a  dog  on  an  exposure 

126 


PHOSGENE  127 

of  30  minutes,  but  0.3  milligram  of  phosgene  will  have  the  same 
effect.  This  of  course  means  that  a  cloud  of  phosgene  contain- 
ing one-eighth  (by  weight)  of  the  concentration  of  a  chlorine 
cloud  will  have  the  same  lethal  properties. 

(5)  Phosgene  is  much  less  reactive  than  chlorine,  so  that 
the  matter  of  protection  becomes  more  difficult.  Fortunately, 
word  was  received  by  the  British  of  the  intended  first  use 
of  phosgene  against  them  and  consequently  they  were  able 
to  add  hexamethylenetetramine  to  the  impregnating  solution 
used  in  the  cloth  masks. 

(c)  The  third,  and  a  very  important,  factor  in  the  use  of 
phosgene  is  the  so-called  delayed  effect.  In  low  concentrations, 
men  may  breathe  phosgene  for  some  time  with  apparently  no 
ill  effects.  Ten  or  twelve  hours  later,  or  perhaps  earlier  if  they 
attempt  any  work,  the  men  become  casualties. 

Pure  phosgene  has  been  used  in  projector  attacks  (described 
in  Chapter  II).  The  substance  has  also  been  used  in  large 
quantities  in  shell;  the  Germans  also  used  shell  containing 
mixtures  with  superpalite  (trichloromethyl  chloroformate)  or 
sneezing  gas   (diphenylchloroarsine). 


I 


Manufacture 


I 


Phosgene  was  first  prepared  by  John  Davy  in  1812,  by 
exposing  a  mixture  of  equal  volumes  of  carbon  monoxide 
and  chlorine  to  sunlight;  Davy  coined  the  name  ** phosgene" 
from  the  part  played  by  light  in  the  reaction.  While  phosgene 
may  be  prepared  in  the  laboratory  by  a  number  of  other 
reactions,  it  was  quite  apparent  that  the  first  mentioned  reac- 
tion is  the  most  economical  of  these  for  large  scale  produc- 
tion. The  reaction  is  a  delicate  one,  hoAvcver,  and  its  application 
equired  extended  investigation. 

The  United  States  was  fortunate  in  that,  for  some  months 
previous  to  the  war,  the  Oldbury  Electrochemical  Company 
had  been  working  on  the  utilization  of  their  waste  carbon 
monoxide  in  making  phosgene.  The  results  of  these  investiga- 
tions were  given  to  the  government  and  aided  considerably  in 
he  early  work  on  phosgene  at  the  Edgewood  plant. 

Of  the  raw  materials  necessary  for  the  manufacture  of  phos- 


128 


CHEMICAL  WARFARE 


gene,  the  chlorine  was  provided,  at  first  by  purchase  from 
private  plants,  but  later  through  the  Edgewood  chlorine  plant. 
After  a  sufficient  supply  of  chlorine  was  assured  the  next 
question  was  how  to  obtain  an  adequate  supply  of  carbon 
monoxide.     A  method  for  this  gas  had  not  been  developed 


Fig.  23. — Furnace  for .  Generating  Carbon  Monoxide. 


on  a  large  scale  because  it  had  never  been  necessary  to  make 
any  considerable  quantity  of  it.  The  French  and  English 
passed  oxygen  up  through  a  gas  producer  filled  with  coke; 
the  oxygen  combines  with  the  carbon,  giving  carbon  monoxide. 
The  oxygen  was  obtained  from  liquid  air,  for  which  a  Claude 
liquid  air  machine  may  be  used.    The  difficulty  with  this  method 


PHOSGENE 


129 


of  preparing  carbon  monoxide  was  that  the  amount  of  heat 
generated  was  so  great  that  the  life  of  the  generators  was  short. 
Our  engineers  conceived  the  idea  of  using  a  mixture  of  carbon 
dioxide  and  oxygen.  The  union  of  carbon  dioxide  with  carbon 
to  form  carbon  monoxide  is  a  reaction  in  which  heat  is  absorbed. 
Therefore  by  using  the  mixture  of  the  two  gases,  the  heat  of 
the   one  reaction  was  absorbed  by  the  second  reaction.     In 


i 

l^-i^i/^r*-     .^^  rn 

i 

1 

1    1 

Fig.  24. — Catalyzer  Boxes  Used  in  the  Manufacture  of  Phosgene. 


i 


this  way  a  very  definite  temperature  could  be  maintained,  and 
She  production  of  carbon  monoxide  was  greatly  increased. 

Carbon  dioxide  was  prepared  by  the  combustion  of  coke, 
he  gas  was  washed  and  then  passed  into  a  solution  of  potas- 
sium carbonate.     Upon  heating,  this  evolved  carbon  dioxide. 

Phosgene  was  then  prepared  by  passing  the  mixture  of  carbon 
monoxide  and  chlorine  into  catalyzer  boxes  (8  feet  long,  2  feet 
9  inches  deep  and  11  inches  wide),  which  are  made  of  iron, 
lined  with  graphite  and  filled  with  a  porous  form  of  carbon. 
Two  sets  of  these  boxes  were  used.  In  the  first  the  reaction 
proceeds  at  room  temperature,  and  is  about  80  per  cent  com- 


130  CHEMICAL  WARFARE 

plete.  The  second  set  of  boxes  were  kept  immersed  in  tanks 
filled  with  hot  water,  and  there  the  reaction  is  completed. 

The  resulting  phosgene  was  dried  with  sulfuric  acid  and 
then  condensed  by  passing  it  through  lead  pipes  surrounded  by 
refrigerated  brine. 

The  Germans  prepared  their  phosgene  by  means  of  a  pre- 
pared charcoal  (wood  or  animal).  Carbon  monoxide  was 
manufactured  by  passing  carbon  dioxide  over  wood  charcoal 
contained  in  gas-fired  muffles  and  was  washed  by  passing 
through  sodium  hydroxide.  This  was  mixed  with  chlorine  and 
the  mixture  passed  downward  through  a  layer  of  about  20  cm. 
of  prepared  charcoal  contained  in  a  cast  iron  vessel  80  cm. 
in  diameter  and  80  cm.  deep.  By  regulating  the  mixture  so 
that  there  was  a  slight  excess  of  carbon  monoxide,  the  phosgene 
was  obtained  with  only  one-quarter  of  one  per  cent  free 
chlorine.  The  charcoal  (wood)  was  prepared  by  washing  with 
hydrochloric  and  other  acids  until  free  from  soluble  ash;  it 
was  then  washed  with  water  and  dried  in  vacuum.  The  size 
of  the  granules  was  about  one-quarter  inch  mesh.  Their  life 
averaged  about  six  months. 

Properties 

Phosgene  is  a  colorless  gas  at  room  temperatures,  but 
becomes  a  liquid  at  8°.  The  odor  of  phosgene  is  suggestive 
of  green  corn  or  musty  hay.  One  liter  of  phosgene  vapor 
weighs  4.4  grams  (chlorine  weights  3.22  grams).  At  0°  C,  the 
liquid  is  heavier  than  water,  having  a  specific  gravity  of  1.432. 
At  25°,  the  vapor  exerts  a  pressure  of  about  25  pounds  per 
square  inch.  Phosgene  is  absorbed  by  solid  materials,  such 
as  pumice  stone  and  celite.  Pumice  stone  absorbs  more  than 
its  own  weight  of  phosgene.  Thus  5.7  grams  of  pumice  absorbed 
7.4  grams  phosgene,  which  completely  evaporated  in  60 
minutes.  German  shell  have  been  found  which  contained  such 
a  mixture  (phosgene  and  pumice  stone).  While  the  apparent 
reason  for  their  use  is  to  prevent  the  rapid  evaporation  of  the 
phosgene,  it  is  a  question  whether  such  is  the  case,  for  a  greater 
surface  is  really  present  in  the  case  of  pumice  stone  than  where 
the  phosgene  is  simply  on  the  ground.     Phosgene  is  slowly 


PHOSGENE  131 

decomposed  by  cold  water,  rapidly  by  hot  water.  This  reaction 
is  important  because  there  is  always  moisture  in  the  air,  which 
would  tend  to  lower  the  concentration  of  the  gas. 

Phosgene  is  absorbed  and  decomposed  by  hexamethylene- 
tetramine  (urotropine).  This  reaction  furnished  the  basis  of 
the  first  protection  used  by  the  British.  Later  the  catalytic 
decomposition  of  phosgene  into  carbon  dioxide  and  hydro- 
chloric acid  by  tlie  charcoal  in  the  mask  furnished  protection. 

For  most  purposes  a  trace  of  chlorine  in  phosgene  is  not 
a  disadvantage;  for  example,  when  it  is  used  in  cylinders  or      / 
projectors.     Under    certain    conditions,    as   when   used   as    a  V 
solvent  for  sneezing  gas,  the   presence  of  chlorine   must  he/\ 
avoided,  since  it  reacts  with  tlic  substance  in  solution,  usually 
producing  a  harmless  material.    Chlorine  may  be  removed  from 
phosgene  by  passing  the  mixture  through  cotton  seed  oil. 

Protection         (     ^ML    V \  \       /  ^ 

It  was  mentioned  above  that  hexametnylenetetramine 
(urotropine)  was  used  in  the  early  pads  (black  veil  and  similar 
masks)  and  flannel  helmets.  This  was  found  to  be  satisfactory 
against  chlorine  and  phosgene,  in  the  concentrations  usually 
found  during  a  cylinder  attack.  The  mixture  used  consisted 
of  urotropine,  sodium  thiosulfate  (''hypo"),  sodium  carbonate 
and  glycerine.  The  glycerine  tended  to  keep  the  pads  moist, 
while  the  other  chemicals  acted  as  protective  agents  against 
the  mixture  of  phosgene  and  chlorine. 

The  introduction  of  the  Standard  Box  Respirator  with  its 
charcoal-soda  lime  filling  increased  very  materially  the  protec- 
tion against  phosgene.  In  this  filling,  the  charcoal  both  absorbs 
the  phosgene  and  catalyzes  the  reaction  with  the  moisture  of 
the  air  with  which  tlie  phosgene  is  mixed,  to  form  hydrochloric 
acid  and  carbon  dioxide.  Soda  lime  absorbs  phosgene  but  does 
not  catalyze  its  decomposition.  This  shows  the  advantage  of 
the  mixture,  since  the  hydrochloric  acid,  which  is  formed 
through  the  action  of  the  charcoal,  is  absorbed  by  the  soda 
lime.  Experiments  seem  to  indicate  that  it  does  not  matter 
which  material  is  placed  in  the  bottom  of  the  canister,  but 
that  an  intimate  mixture  is  the  best  arrangement.     Using  a 


132  CHEMICAL  WARFARE 

concentration  of  5,000  parts  per  million  (20.2  mg.  per  liter) 
a  type  H  canister  (see  page  217)  will  give  complete  protection 
for  about  40  minutes;  when  the  air-gas  mixture  passes  at  the 
rate  of  16  liters  per  minute  the  efficiency  or  life  of  a  canister 
increases  with  a  decrease  in  temperature,  as  is  seen  in  the 
following  table  (the  concentration  was  5,000  parts  per  million, 
the  rate  of  flow  16  liters  per  minute) 


Temperature 

Efficiency 

°C. 

(Time  in  minutes) 

-10 

223 

0 

172 

10 

146 

20 

130 

30 

125 

40 

99 

From  these  figures  it  is  seen  that  at  —10°  C.  the  life  is  about 
50  per  cent  greater  than  at  summer  temperature.  As  would 
be  expected  the  life  of  a  canister  is  shortened  by  increasing 
the  concentration  of  phosgene  in  the  phosgene  air  mixture. 
This  is  illustrated  by  the  following  figures: 


Concentration 

Life 

p.p.m. 

(Time  in  minutes) 

5,000 

177 

10,000 

112 

15,000 

72 

20,000 

58 

25,000 

25 

(25,000  p.p.m.  is  equal  to  101.1  mg.  per  liter.) 

There  is  rather  a  definite  relation  between  the  concentration 
of  the  gas  and  the  life  of  a  canister  at  any  given  rate  of  flow. 
Many  of  these  relations  have  been  expressed  by  formulas  of  which 
the  following  is  typical.  At  32  liters  per  minute  flow, 
(.0.9  X  T  =  101,840,  in  which  c  is  the  concentration  and  t  the 
time. 

Shell  Filling 

The  empty  shell,   after  inspection,  are  loaded  on  trucks, 

\together  with  the  appropriate  number  of  ** boosters,"  which 
screw  into  the  top  of  the  shell  and  thereby  close  them.     The 


PHOSGENE  133 

trucks  are  run  by  an  electric  storage  battery  locomotive  to 
Xhe  filling  unit.  The  shell  are  transferred  by  hand  to  a  con- 
veyor, which  carries  the  shell  slowly  through  a  cold  room. 
During  this  passage  of  about  30  minutes,  the  shell  are  cooled 
to  about  0°  F.  The  cooled  shell  are  transferred  to  shell  trucks, 
each  truck  carrying  6  shell.  These  trucks  are  drawn  through 
the  filling  tunnel  by  means  of  a  chain  haul  operated  by  an 


1 

^^^^^^^^^^^" ,.,^H  1 

^^ 

^^M  '~^r|| 

iP! 

WIM 

Fig.  25. — Filling  Livens  Urums  with  Phosgene. 

air  motor  to  the  filling  machine.  Here  the  liquid  phosgene 
is  run  into  the  shell  by  automatic  machines,  so  arranged  that 
the  6  shell  are  at  the  same  time  automatically  filled  to  a  con- 
stant void.  The  truck  then  carries  the  filled  shell  forward 
a  few  feet  to  a  small  window,  at  which  point  the  boosters 
are  inserted  into  the  nose  of  the  shell  by  hand.  The  final 
closing  of  the  shell  is  then  effected  by  motors  operated  by 
compressed  air.  The  filling  and  closing  machines  are  all 
operated  by  workmen  on  the  outside  of  the  filling  tunnel. 

The  filled  shell  are  conveyed  to  the  shell  dump,  where  they 
are  stored  for  24  hours,  nose  down  on  skids,  in  order  to  test 
for  leaks. 


134 


CHEMICAL  WARFARE 
J      Tactical  Use 


Phosgene  was  first  used  in  cloud  attacks  in  December,  1915. 
These  attacks  continued  for  about  nine  months  and  were  then 
gradually  replaced,  to  a  large  extent,  by  gas  shell  attacks. 
Phosgene  was  first  found  in  German  projectiles  in  November, 
1916.  These  shell  were  known  as  the  d  shell.  Besides  pure 
phosgene,  mixtures  of  phosgene  and  chloropicrin,  phosgene  and 


Fig.  26. — Interior  of  a  Shell  Dump. 

superpalite,  and  phosgene  and  diphenylchloroarsine  have  been 
found. 

The  English  introduced  the  use  of  projectors  in  the  Spring 
of  1917.  They  have  a  decided  advantage  over  shell  in  that 
they  hold  a  larger  volume  of  gas  and  readily  lend  themselves 
to  surprise  attacks.  As  the  Germans  say,  *'the  projector  com- 
bines the  advantages  of  gas  clouds  and  gas  shell.  The  density 
is  equal  to  that  of  gas  clouds  and  the  surprise  effect  of  shell 
fire  is  also  obtained." 

Toward  the  close  of  the  war,  the  Germans  made  use  of 


PHOSGENE  135 

a  mixture  of  phosgene  and  pumice  stone.  A  captured  projector 
contained  about  13  pounds  of  phosgene  and  51/2  pounds  of 
pumice.  There  seems  to  be  some  question  as  to  the  value  of 
such  a  procedure.  Lower  initial  concentrations  are  secured; 
this  is  due,  in  part  of  course,  to  the  smaller  volume  of  phosgene 
in  the  shell  containing  pumice.  Pumice  does  seem  to  keep 
the  booster  from  scattering  the  phosgene  so  high  into  the  air, 
and  at  the  same  time  does  not  prevent  the  phosgene  from 
being  liberated  in  a  gaseous  condition.  This  would  indicate 
that  pumice  gives  a  more  even  and  uniform  dispersion  and 
a  more  economical  use  of  the  gas  actually  used. 

Owing  to  its  non-persistent  nature  (the  odor  disappears 
in  from  one  and  a  half  to  two  hours)  and  to  its  general  proper- 
ties, phosgene  really  forms  an  ideal  gas  to  produce  casualties. 


,^^'M 


Action  on  Man 

Phosgene  acts  both  as  a  direct  poison  and  as  a  strong  lung 
irritant,  causing  rapid  filling  of  the  lungs  with  liquid.  The 
majority  of  deaths  are  ascribed  to  the  filling  up  of  the  lungs 
and  consequently  to  the  suffocation  of  the  patients  through 
lack  of  air.  This  filling  up  of  the  lungs  is  greatly  hastened 
by  exercise.  Accordingly,  all  rules  for  the  treatment  of 
patients  gassed  with  phosgene  require  that  they  immediately 
lie  down  and  remain  in  that  position.  They  are  not  even 
allowed  to  walk  to  a  dressing  station.  The  necessity  of  absolute 
quiet  for  gassed  patients  undoubtedly  partly  accounts  for  the 
later  habit  of  carrying  out  a  prolonged  bombardment  after 
a  heavy  phosgene  gas  attack.  The  high  explosive  causes  eon- 
fusion,  forcing  the  men  to  move  about  more  or  less  and  prac- 
tically prevents  the  evacuation  of  the  gassed.  In  the  early 
days  of  phosgene  the  death  rate  was  unduly  high  because  of 
lack  of  knowledge  of  this  action  of  the  gas.  Due  to  the 
decreased  lung  area  for  oxygenizing  the  air,  a  fearful  burden 
is  thrown  on  the  heart,  and  accordingly,  those  with  a  heart 
at  all  weak  are  apt  to  expire  suddenly  when  exercising  after 
being  gassed. 

As  an  illustration  of  the  delayed  action  of  phosgene,  a  large 
scale  raid  made  by  one  of  the  American  divisions  during  its 
training  is  highly  illuminating. 

ft 


136  CHEMICAL  WARFARE 

This  division  decided  to  make  a  raid  on  enemy  trenches 
which  were  situated  on  the  opposite  slope  of  a  hill  across  a 
small  valley.  Up  stream  from  both  of  the  lines  of  trenches 
was  a  French  village  in  the  hands  of  the  Germans.  When  the 
attack  was  launched  the  wind  was  blowing  probably  six  or 
seven  miles  per  hour  directly  down  stream  from  the  village, 
i.e.,  directly  toward  the  trenches  to  be  attacked.  The  usual 
high  explosive  box  barrage  was  put  around  the  trenches  it 
was  intended  to  capture. 

Three  hundred  Americans  made  the  attack.  During  the 
attack  a  little  more  than  three  tons  of  liquid  phosgene  was 
thrown  into  the  village  in  75-  and  155-millimeter  shells.  Tlie 
nearest  edge  of  the  village  shelled  with  phosgene  was  less  tlian 
700  yards  from  the  nearest  attacking  troops.  None  of  tlic 
troops  noticed  the  smell  of  phosgene,  although  the  fumes  from 
high  explosive  were  so  bad  that  a  few  of  the  men  adjusted 
their  respirators.  The  attack  was  made  about  3  a.m.,  the  men 
remaining  about  45  minutes  in  the  vicinity  of  the  German 
trenches.  The  men  then  returned  to  their  billets,  some  five 
or  six  kilometers  back  of  the  line.  Soon  after  arriving  there, 
that  is  in  the  neighborhood  of  9  a.m.,  the  men  began  to  drop, 
and  it  was  soon  discovered  that  they  were  suffering  from  gas 
poisoning.  Out  of  the  300  men  making  the  attack  236  were 
gassed,  four  or  five  of  whom  died. 

The  Medical  Department  was  exceedingly  prompt  and 
vigorous  in  the  treatment  of  these  cases,  which  probably 
accounted  for  the  very  low  mortality. 

This  is  one  of  the  most  interesting  cases  of  the  delayed 
action  that  may  occur  in  gassing  from  phosgene.  Here  the 
concentration  was  slight  and  there  is  no  doubt  its  effectiveness 
was  largely  due  to  the  severe  exercise  taken  by  the  men  during 
and  after  the  gassing. 

It  should  be  remarked  in  closing  that  while  gas  officers 
were  not  consulted  in  the  planning  of  this  attack,  a  general 
order  was  shortly  thereafter  issued  requiring  that  gas  officers 
be  consulted  whenever  gas  was  to  be  used. 


CHAPTER   VII 
LACHRYMATORS 

Without  question  the  eyes  are  the  most  sensitive  part  of 
the  body  so  far  as  ehofiaical  warfare  is  concerned.  Lachry- 
mators  are  substances  which  affect  the  eyes,  causing  involun- 
tary weeping.  These  substances  can  produce  an  intolerable 
atmosphere  in  concentrations  one  thousand  times  as  dilute 
as  that  required  for  the  most  effective  lethal  agent.  The  great 
military  value  of  these  gases  has  already  been  mentioned  and 
will  be  discussed  more^fully  later. 

There  are  a  number  of  compounds  which  have  some  value 
as  lachrymators,  though  a  few  are  very  much  better  than  all 
the  others.  Practically  all  of  them  have  no  lethal  properties 
in  the  concentrations  in  which  they  are  efficient  lachrymators, 
though  we  must  not  lose  sight  of  the  fact  that  many  of  them 
liave  a  high  lethal  value  if  the  concentration  is  of  the  order 
of  the  usual  poison  gas.  The  lachrymators  are  used  alone 
when  it  is  desired  to  neutralize  a  given  territory  or  simply  to 
harrass  the  enemy.  At  other  times  they  are  used  with  lethal 
gases  to  force  the  immediate  or  to  prolong  the  wearing  of  the 
mask. 

A  large  number  of  the  lachrymators  contain  bromine.  In 
order  to  maintain  the  gas  warfare  requirements,  it  was  early 
decided  that  the  bromine  supply  would  have  to  be  considerably 
increased.  The  most  favorable  source  of  bromine  is  the  sub- 
terranean basin  found  in  the  vicinity  of  Midland,  Michigan. 
Because  of  the  extensive  experience  of  the  Dow  Chemical  Co. 
in  all  matters  pertaining  to  the  production  of  bromine,  they 
were  given  charge  of  the  sinking  of  seventeen  government 
wells,  capable  of  producing  650,000  pounds  of  bromine  per 
year.  While  the  plant  was  not  operated  during  the  War,  it  was 
later    operated    to    complete    a    contract    for    500,000    pounds 

137 


138  CHEMICAL  WARFARE 

of  bromine  salts.     They  will  be  held  as  a  future  war  asset  of 
the  United  States. 

The  principal  lachrymators  used  during  the  War  were : 

Bromoacetone, 
Bromomethylethylketone, 
Benzyl  bromide^ 
Ethyl  iodoacetate, 
Bromobenzyl  cyanide, 
Phenyl  carbylamine  chloride. 

Chloropicrin  is  something  of  a  lachrymator,  but  it  has  greater 
value  as  a  toxic  gas. 

Halogenated  Ketones 

One  of  the  earliest  lachrymators  used  was  bromoacetone. 
Because  of  the  difficulty  of  obtaining  pure  material,  the  com- 
mercial product,  containing  considerable  dibromoacetone  and 
probably  higher  halogenated  bodies,  was  used.  The  presence 
of  these  higher  bromine  derivatives  considerably  decreased  its 
efficiency  as  a  lachrymator.  The  preparation  of  bromoace- 
tone involved  the  loss  of  considerable  bromine  in  the  form  of 
hydrobromic  acid.  This  led  the  French  to  study  various 
methods  of  preparation,  and  they  finally  obtained  a  product 
containing  80  per  cent  bromoacetone  and  20  per  cent  chloro- 
acetone,  which  they  called  "martonite."  As  the  war  pro- 
gressed, acetone  became  scarce,  and  the  Germans  substituted 
methylethylketone,  for  which  there  was  little  use  in  other  war 
activities.    This  led  to  the  French  ' '  homomartonite. " 

Various  other  halogen  derivatives  of  ketones  have  been 
studied  in  the  laboratory,  but  none  have  proven  of  as  great 
value  as  bromoacetone,  either  from  the  standpoint  of  toxicity 
or  lachrymatory  power. 

Bromoacetone  may  be  prepared  by  the  action  of  bromine 
(liquid  or  vapor)  upon  acetone  (with  or  without  a  solvent). 
Aqueous  solutions  of  acetone,  or  potassium  bromide  solutions 
of  bromine,  have  also  been  used. 

Pure  bromoacetone  is  a  water  clear  liquid.  There  are  great 
differences  in  the  properties  ascribed  to  this  body  by  different 


tf 


LACHRYMATORS  139 

investigators.  This  probably  is  due  to  the  fact  that  the  mono- 
bromo  derivative  is  mixed  with  those  containing  two  or  more 
toms  of  bromine.  A  sample  boiling  at  126-127°  and  melting 
t  —54°,  had  a  specific  gravity  of  1.631  at  0°.  It  has  a  vapor 
pressure  of  9  mm.  of  mercury  at  20°. 

While  bromoacetone  is  a  good  lachrymator,  it  possesses 
the  disadvantage  that  it  is  not  very  stable.  Special  shell 
linings  are  necessary,  and  even  then  the  material  may  be 
decomposed  before  the  shell  is  fired.  The  Germans  used  a  lead 
lined  shell,  while  considerable  work  has  been  carried  out  in 
this  country  with  enamel  lined  shell.  Glass  lined  shell  may 
also  be  used.  It  is  interesting  to  note  that,  while  bromoacetone 
decomposes  upon  standing  in  the  shell,  it  is  stable  upon  detona- 
tion. No  decomposition  products  are  found  after  the  explosion, 
and  even  unchanged  liquid  is  found  in  the  shell.  It  may 
be  considered  as  having  a  low  persistency,  since  the  odor 
entirely  disappears  from  the  surface  of  the  ground  in  twenty- 
four  hours. 

Bromoacetone  was  also  used  by  the  Germans  in  glass  hand 
grenades  (Hand-a-Stink  Kugel)  and  later  in  metal  grenades. 
The  metal  grenades  weighed  about  two  pounds  and  contained 
about  a  pound  and  a  half  of  the  liquid. 

Martonite  was  prepared  by  the  French  in  an  attempt  more 
completely  to  utilize  the  bromine  in  the  preparation  of  bromo- 
acetone. They  regenerated  the  bromine  by  the  use  of  sodium 
chlorate : 

NaClOa  +  6HBr  ±=  NaCl  +  3Br2  +  SH^O 

[n  practice  sulfuric  acid  is  used  with  the  sodium  chlorate,  so  that 
the  final  products  are  sodium  acid  sulfate  and  a  mixture  of  20  per 
cent  chloroacetone  and  80  per  cent  bromoacetone,  according  to 
the  reaction: 

5  (CH3)2CO+4Br+H2S04+NaC103  = 
4CH2BrCOCH3+CH2ClCOCH3+NaHS04+3H20. 

This  product  is  equally  as  effective  as  bromoacetone  alone  and 
is  very  much  cheaper  to  manufacture.  In  general  its  properties 
resemble  very  closely  those  of  bromoacetone. 


140  CHEMICAL  WARFARE 

German  Manufacture  of  Bromo acetone  and  Bromomethylethyl 

KETONE* 

These  two  products  were  prepared  by  identical  methods.  About 
two-thirds  of  the  product  produced  by  the  factory  was  prepared  from 
methylethyl  ketone  which  was  obtained  from  the  product  resulting  from 
the  distillation  of  wood.  The  method  employed  was  to  treat  an  aqueous 
solution  of  potassium  or  sodium  chlorate  with  acetone  or  methylethyl 
ketone,  and  then  add  slowly  the  required  amount  of  bromine.  The 
equation  for  the  reaction  in  the  case  of  acetone  is  as  follows: 

CH3COCH3  +  Br2  =  CH2BrCOCH3  +  HBr 

Ten  kg.-mols  of  acetone  or  methylethyl  ketone  were  used  in  a 
single  operation.  About  10  per  cent  excess  of  chlorate  over  that 
required  to  oxidize  the  hydrobromic  acid  formed  in  the  reaction  was 
used.  The  relation  between  the  water  and  the  ketone  was  in  the 
proportion  of  2  parts  by  weight  of  the  former  to  1  part  by  weight 
of  the  latter.  For  1  kg.  mol.-wt.  of  the  ketone,  10  per  cent  excess 
over  1  kg.  atomic-weight  of  bromine  was  used. 

The  reaction  was  carried  out  either  in  earthenware  vessels  or  in 
iron  kettles  lined  with  earthenware.  The  kettles  were  furnished  with 
a  stirrer  made  of  wood,  and  varied  in  capacity  from  4,000  to  5,000  liters. 
They  were  set  in  wooden  tanks  and  cooled  by  circulating  water.  The 
chlorate  was  first  dissolved  in  the  water  and  then  the  ketone  added. 
Into  this  mixture  the  bromine  was  allowed  to  run  slowly  while  the 
solution  was  stirred  and  kept  at  a  temperature  of  from  30°  to  40°  c. 
The  time  required  for  the  addition  of  the  bromine  was  about  48  Lrs. 
When  the  reaction  was  complete,  the  oil  was  drawn  off  into  an  iron 
vessel  and  stirred  with  magnesium  oxide  in  the  presence  of  a  small 
amount  of  water  in  order  to  neutralize  the  free  acid.  It  was  then 
separated  and  dried  with  calcium  chloride.  At  this  point  a  sample 
of  the  material  was  taken  and  tested.  The  product  was  distilled 
to  tell  how  much  of  it  boiled  over  below  130°  when  methylethyl  ketone 
had  been  used.  If  less  than  10  per  cent  distilled  over,  the  bromination 
was  considered  to  be  satisfactory.  If,  however,  a  larger  percentage  of 
low-boiling  material  was  obtained,  the  product  was  submitted  to  further 
bromination.  The  material  obtained  in  this  way  was  found  on  analysis 
to  contain  slightly  less  than  the  theoretical  amount  of  monobromo- 
ketone. 

It  was  finally  transferred  by  suction  or  by  pressure  into  tank- 
wagons.     At  first  lead-lined  tanks  were  used,  but  later  it  was  found 

♦Norris,  J.  Ijid.  Eng.  Chem.,  11,  828  (1919). 


I 


LACHRYMATORS  141 

that  tanks  made  of  iron  could  be  substituted.  In  order  to  take  care 
of  the  small  amount  of  hydrobromic  acid,  which  is  slowly  formed, 
a  small  amount  of  magnesium  oxide  was  added  to  the  material.  The 
amount  of  the  oxide  used  was  approximately  in  the  proportion  of 
1  part  to  1000  parts  of  ketone.  When  the  magnesium  oxide  was  used, 
it  was  found  that  the  bromoketone  kept  without  appreciable  decomposi- 
tion for  about  2  months.  The  yield  of  the  product  from  580  kg.  of 
acetone  (10  kg.-mol.  wts.)  was  1,100  kg.  The  yield  from  720  kg.  of 
methylethyl  ketone  (10  kg.-mol.  wts.)  was  1,250  kg. 

Haloqenated  Esters 

The  use  of  ethyl  iodoacetate  was  advocated  at  a  time  when 
the  price  of  bromine  seemed  prohibitive.  Because  of  the  rela- 
tive price  of  bromine  and  iodine  under  ordinary  conditions, 
it  is  not  likely  that  it  would  be  commonly  used.  However, 
it  is  an  efficient  lachrymator  and  is  more  stable  than  the 
halogenated  ketones,  so  that  on  a  smaller  scale  it  might  be 
advisable  to  use  it. 

It  is  prepared  by  the  reaction  of  sodium  iodide  upon  an 
alcoholic  solution  of  ethyl  chloroacetate.  It  is  a  colorless  oil, 
boiling  at  178-180°  C.  (69°  C.  at  12  mm.)  and  having  a 
density  of  about  1.8.  It  is  very  much  less  volatile  than  bromo- 
acetone,  having  a  vapor  pressure  of  0.54  mm.  of  mercury  at 
20°  C.  Ethyl  iodoacetate  is  about  one-third  as  toxic  as  bromo- 
acetone,  but  has  about  the  same  lachrymatory  value. 

Aromatic  HALroEs 

'* Benzyl  bromide''  was  also  used  during  the  early  part  of 
the  war,  usually  mixed  with  bromoacetone.  The  material  was 
not  pure  benzyl  bromide,  but  the  reaction  product  of  bromine 
upon  xylene,  and  should  perhaps  be  referred  to  as  *'xylyl 
bromide. ' ' 

Pure  benzyl  bromide  is  a  colorless  liquid,  boiling  at  198- 
199°  C,  and  having  an  odor  reminiscent  of  water  cress  and  then 
of  mustard  oil.  The  war-gas  is  probably  a  mixture  of  mono- 
and  dibromo  derivatives,  boiling  at  210-220°  C.,  and  having  a 
density  at  20°  C.  of  1.3.  The  mixture  of  benzyl  and  xylyl 
bromides  used  by  the  Germans  was  known  as  "T-Stoff,"  while 


142  CHEMICAL   WARFARE 

the  mixture  of  88  per  cent  xylyl  bromide  and  12  per  cent 
bromoacetone  was  called  ''Green  T-Stoff." 

As  in  the  case  of  the  halogenated  acetones,  it  is  necessary 
to  use  lead  lined  shell  for  these  compounds.  Enamel  and 
glass  lined  shell  may  be  used  and  give  good  results.  "While 
they  are  difficult  of  manufacture,  satisfactory  methods  were 
being  developed  at  the  close  of  the  war. 

''T-Stoff"  may  be  detected  by  the  nose  in  concentrations 
of  one  part  in  one  hundred  million  of  air,  and  will  cause 
profuse  lachrymation  with  one  part  in  a  million.  It  is  a  highly 
persistent  material  and  may  last,  under  favorable  circum- 
stances, for  several  days.  While  it  is  relatively  non-toxic, 
French  troops  were  rendered  unconscious  by  it  during  certain 
bombardments  in  the  Argonne  in  the  summer  of  1915. 

A  number  of  derivatives  of  the  benzyl  halides  have  been 
tested  and  some  have  proven  to  be  very  good  lachrymators. 
The  difficulty  of  their  preparation  on  a  commercial  scale  has 
made  it  inadvisable  to  use  them,  and  especially  inasmuch  as 
bromobenzyl  cyanide  has  proven  to  be  such  a  valuable  com- 
pound. 

Bromobenzyl  Cyanide 

Bromobenzyl  cyanide  is,  chemically,  a-bromo-a-tolunitrile, 
or  phenyl-bromo-acetonitrile,  CgHsCHBrCN.  It  is  prepared 
by  the  action  of  bromine  upon  benzyl  cyanide. 

Benzyl  cyanide  is  prepared  by  the  action  of  sodium  cyanide 
upon  a  mixture  of  equal  parts  of  95  per  cent  alcohol  and 
benzyl  chloride.  The  benzyl  chloride  in  turn  is  obtained  by 
the  chlorination  of  toluene  at  100°.  The  material  must  be 
fairly  pure  in  order  that  the  benzyl  cyanide  reaction  may  pro- 
ceed smoothly.  The  cyanide  is  subjected  to  a  fractional  dis- 
tillation and  that  part  boiling  within  3  degrees  (the  pure 
product  boils  at  231.7°  C.)  is  treated  with  bromine  vapor  mixed 
with  air.  It  has  been  found  necessary  to  catalyze  the  reaction 
by  sunlight,  artificial  light  or  the  addition  of  a  small  amount 
of  bromobenzyl  cyanide. 

The  product  obtained  from  this  reaction,  if  the  hydro- 
bromic  acid  which  is  formed  is  carefully  removed  by  a  stream 


LACHRYMATORS  143 

fof  air,  is  sufficiently  pure  for  use  as  a  lachrymator.  It  melts 
from  16  to  22°  C,  while  the  pure  product  melts  at  29°  C.  It  can- 
not be  distilled,  even  in  a  high  vacuum.  It  has  a  low  vapor  pres- 
sure and  thus  is  a  highly  persistent  lachrymator. 
k  Bromobenzyl  cyanide  is  about  as  toxic  as  chlorine,  but  is 
^many  times  as  effective  a  lachrymator  as  any  of  the  halogenated 
ketones  or  aromatic  halides  studied.  It  has  a  pleasant  odor 
and  produces  a  burning  sensation  on  the  mucous  membrane. 

Like  the  other  halogen  containing  compounds,  lead  or 
enamel  lined  shell  are  necessary  for  preserving  the  material 
any  length  of  time.  In  all  of  this  work  the  United  States 
was  at  a  very  marked  disadvantage.  While  the  Allies  and 
the  Germans  could  prepare  substances  of  this  nature  and  use 
them  in  shell  within  a  month,  the  United  States  was  sure  that 
shell  filled  at  Edgewood  Arsenal  probably  would  not  be  fired 
within  three  months.  This  means  that  much  greater  precautions 
were  necessary,  both  as  to  the  nature  of  the  shell  lining  and 
as  to  the  purity  of  the  **war  gas.*' 

The  question  of  protection  against  lachrymatory  gases  was 
never  a  serious  one.  During  the  first  part  of  the  war  this 
was  amply  supplied  by  goggles.  Later,  when  the  Standard 
Respirator  was  introduced,  it  was  found  that  ample  protection 
was  afforded  against  all  the  lachrymators.  Their  principal 
value  is  against  unprotected  troops  and  in  causing  men  to 
wear  their  masks  for  long  periods  of  time. 

The  comparative  value  of  the  various  lachrymators  men- 
tioned above  is  shown  in  the  following  table: 

Bromobenzyl  cyanide 0 .  0003 

Martonite 0.0012 

Ethyl  iodoacetate 0.0014 

Bromoacetone 0.0015 

Xylyl  bromide ;  . .  0 .  0018 

Benzyl  bromide 0.0040 

Bromo  ketone 0 . Oil 

Choroacetone 0. 018 

Chloropicrin 0 .  019 

The  figures  give  tlie  concentration  (milligram  per  liter  of 
air)  necessary  to  produce  lachrymation.  The  method  used  in 
obtaining  these  figures  is  given  in  Chapter  XXI. 


CHAPTER   VIII 
CHLOROPICRIN 

During  the  spring  of  1917,  strange  reports  came  from  the 
Italian  front  that  the  Germans  were  using  a  new  war  gas. 
This  gas,  while  it  did  not  seem  to  be  very  poisonous,  had  the 
combined  property  of  being  a  lachrymator  and  also  of  causing 
vomiting.  Large  number  of  casualties  resulted  through  the 
men  being  forced  to  remove  their  masks  in  an  atmosphere  filled 
with  lethal  gases.  The  gas  had  the  additional  and  serious/ 
disadvantage  of  being  a  very  difficult  one  to  remove  completely 
in  the  gas  mask.  The  first  'American  masks  were  very  good 
when  chlorine  or  phosgene  was  considered  but  were  of  no  value 
when  chloropicrin  was  used. 

One  of  the  interesting  facts  of  chemical  warfare  is  that 
few  if  any  new  substances  were  discovered  and  utilized  during 
the  three  years  of  this  form  of  fighting.    Chlorine  and  phosgene  \ 
w^ere  well  known  compounds.    And  likewise,  chloropicrin  -v^as   \ 
an  old  friend  of  the  organic  chemist.    So  much  so,  indeed,  that 
several  organic  laboratories  prepared  the  compound  in  their    \ 
elementary  courses. 

Chloropicrin  was  first  prepared  by  the  English  chemist, 
Stenhouse,  in  1848,  by  the  action  of  bleaching  powder  upon  a 
solution  of  picric  acid.  This  was  followed  by  a  careful  study 
of  its  physical  and  chemical  properties,  few  of  which  have 
any  connection  with  its  use  as  a  poison  gas.  The  use  of  picric 
acid  as  an  explosive  made  it  very  desirable  that  other  raw 
materials  should  be  used.  Chloroform,  which  is  the  ideal  source 
theoretically  (since  chloropicrin  is  nitro-chloroform,  CI3CNO2), 
gave  very  poor  yields.  While  it  may  be  prepared  from  ace- 
tone, in  fair  yields,  acetone  was  about  as  valuable  during  the 
war  as  was  picric  acid.  Practically  all  the  chloropicrin  used 
was  prepared  from  this  acid  as  the  raw  material. 

144 


CHLOROPICRIN 


145 


Manufacture 

In  the  manufacture  of  chloropicrin  the  laboratory  method  was 
adopted.  This  consisted  simply  in  passing  live  steam  through  a 
mixture  of  picric  acid  and  bleaching  powder.  The  resulting 
chloropicrin  passes  out  of  the  still  with  the  steam.  There  was  a 
question  at  first  whether  a  steam  jacketed  reaction  vessel  should 
be  used,  and  whether  stirrers  should  be  introduced.    Both  types 


i 


Fig.  27. — Interior  of  Chloropicrin  Plant. 

were  tested,  of  which  the  simpler  form,  without  .steam  jacket  or 
stirrer,  proved  the  more  efficient. 

The  early  work  was  undertaken  at  the  plant  of  the  Ameri- 
can Synthetic  Color  Company  at  Stamford,  Connecticut.  Later 
a  large  plant  was  constructed  at  Edgewood  Arsenal.  At  the 
latter  place  ten  stills,  8  by  18  feet,  were  erected,  together  with 
the  necessary  accessory  equipment.  The  following  method  of 
operation  was  used : 

The  bleach  is  mixed  with  water  and  stirred  until  a  cream 
is  formed.  This  cream  is  then  pumped  into  the  still  along 
ith  a  solution  of  calcium  picrate  (picric  acid  neutralized  with 


146  CHEMICAL   WARFARE 

lime).  "When  the  current  of  live  steam  is  a,dmitted  at  the 
bottom  of  the  still,  the  temperature  gradually  rises,  until  at 
85°  C.  the  reaction  begins.  The  chloropicrin  passes  over  with  the 
steam  and  is  condensed.  Upon  standing,  the  chloropicrin  set- 
tles out,  and  may  be  drawn  off  and  is  then  ready  for  filling 
into  the  shell.  The  yield  was  about  1.6  times  the  weight  of 
picric  acid  used. 

Properties 

Chloropicrin  is  a  colorless  oil,  which  is  insoluble  in 
water,  and  which  can  be  removed  from  the  reaction  by 
distillation  wth  steam.  It  boils  at  112°  C.  and  will  solidify 
at  —69°  C.  At  room  temperature  it  has  a  density  of  1.69 
and  is  thus  higher  than  chloroform  (1.5)  or  carbon  tetrachloride 
(1.59).  At  room  temperature  it  has  a  vapor  pressure  of  24 
mm.  of  mercury.  It  thus  lies,  in  persistency,  between  such 
gases  as  phosgene  on  the  one  hand,  and  mustard  gas  on  the 
other,  but  so  much  closer  to  phosgene  that  it  is  placed  in  the 
phosgene  group. 

Chloropicrin  is  a  very  stable  compound  and  is  not  decom- 
posed by  water,-  acids  or  dilute  alkalies.  The  reaction  with 
potassium  or  sodium  sulfite,  in  which  all  the  chlorine  is  found 
as  potassium  or  sodium  chloride,  has  been  used  as  an  analytical 
method  for  its  quantitative  determination.  The  qualitative  test 
usually  used  consists  in  passing  the  gas-air  mixture  through  a 
heated  quartz  tube,  which  liberates  free  chlorine.  The  chlorine 
may  be  detected  by  passing  through  a  potassium  iodide  solution 
containing  starch,  or  by  the  use  of  a  heated  copper  wire  gauze, 
when  the  characteristic  green  color  is  obtained. 

An  interesting  physiological  test  has  also  been  developed. 
The  eye-  has  been  found  to  be  very  sensitive  to  chloropicrin. 
The  gas  affects  the  eye  in  such  a  way  that  its  closing  is  prac- 
tically involuntary.  A  measurable  time  elapses  between  the 
instant  of  exposure  and  the  time  when  the  eye  closes.  Below 
1  or  2  parts  per  million^  the  average  eye  withstands  the  gas 
without  being  closed,  though  considerable  blinking  may  be 
caused.  Above  25  parts,  the  reaction  is  so  rapid  as  to  render 
proper  timing  out  of  the  question.  But  with  concentrations 
between  2  and  25  parts,  the  subject  will  have  an  overpowering 


CHLOROPICRIN 


147 


impulse  to  close  his  eye  within  3  to  30  seconds.  The  time 
may  be  recorded  by  a  stop  watch  and  from  the  values  thus 
determined  a  calibration  curve  may  be  plotted,  using  the  con- 
centration in  parts  per  million  and  the  time  to  zero  eye  reaction. 
Typical  figures  are  given  below.  It  will  be  noted  that  different 
individuals  will  vary  in  their  sensitivity,  though  the  order  is 
the  same. 


Cone. 

A 

B 

p.p.m. 

Seconds 

Seconds 

20.0 

4.0 

5.0 

15.0 

5.4 

5.4 

10.0 

7.5 

7.5 

7.5 

9.0 

10.0 

5.0 

13.0 

15.0 

2.5. 

18.0 

30.0 

22 
20 

oj  16 

5  11 


o  10 

Is 


I. 


• 

Carve 

Snbject 

Eye 

— c 

\1 

UeutEector 

Pvt.ProKr 

Pvt.WhitUe»ej 

Right 
Left 
Right 
Right 



1 

> 

. 

« 

^\ 

\\ 

, 

^ 

'V 

^^ 

• 

\^ 

1 

w 

•- 

— 

— 

— 



\. 

.  o 

S 

^ 

^o-. 

— . 

■ 

) 

■^-.. 

er— 

^ 

■^■^ 

— ~ 

~  — 

— ( 

3 

! 

r — 

^ 

"^ 

r- 

2       4       6       8       10      12      14      16      18     20      22      24     2C      28 
Time    In  Seconds 


32     34 


Fig.  28. — Calibration  Curve  of  Eyes  for  Chloropicrin. 

c/    Protection 

Because  of  the  stability  of  chloropicrin,  the  question  of 
protection  resolves  itself  into  finding  an  absorbent  which  is 
very  efficient  in  removing  the  gas  from  air  mixtures.     For- 


148  CHEMICAV  WARFARE 

tunately  such  an  agent  was  found  in  the  activated  charcoal 
used  in  the  American  gas  mask.  The  removal  of  the  gas 
appears  to  take  place  in  two  stages.  In  the  first,  the  gas  is 
adsorbed  in  such  a  way  that  the  long  continued  passage  of 
air  does  not  remove  it.  In  the  second,  the  gas  is  absorbed, 
and  this,  really  excess  gas,  is  removed  by  pure  air  passing 
over  the  charcoal.  The  relation  of  these  two  factors  has  an 
important  bearing  on  the  quality  of  charcoal  to  be  used  in 
gas  masks.  It  appears  that  up  to  a  certain  point  an  increase 
of  the  quality  is  desirable :  beyond  this,  it  is  of  doubtful  value. 

Unlike  phosgene,  chloropicrin  is  absorbed  equally  well  at 
all  temperatures.  Moisture  on  the  other  hand  has  a  very 
decided  effect.  It  appears  that  charcoal  absorbs  roughly 
equivalent  weights  of  chloropicrin  and  of  water;  the  presence 
of  water  in  the  charcoal  thus  displaces  an  approximately  equal 
amount  of  chloropicrin. 

In  the  study  of  canisters  it  has  been  found  that  the  efficiency 
time  is  approximately  inversely  proportional  to  the  concentra- 
tion. Formulas  have  been  calculated  to  express  the  relation 
existing  between  concentration  and  life  of  the  canister,  and 
also  between  the  rate  of  flow  of  the  gas  and  the  life. 

While  water  seems  to  have  a  decidedly  marked  effect  upon 
the  life  of  a  canister,  this  is  not  true  of  other  gases,  and  the 
efficiency  of  the  canister  for  each  gas  is  not  decreased  when 
used  in  a  binary  mixture. 

Tactical  Uses 

Because  of  the  hifeh  boiling  point  of  chloropicrin  it  can 
only  be  used  in  shell.  The  German  shell  usually  contained 
a  mixture  of  superpalite  (trichloromethyl  chloroformate)  and 
chloropicrin,  the  relative  proportions  being  about  75  to  25. 
These  were  called  Green  Cross  Shell,  from  the  peculiar  marking . 
on  the  outside  of  the  shell.  Mixtures  of  phosgene  and  chloro- 
picrin (50-50)  have  also  been  used. 

The  Allies  have  used  a  mixture  of  80  per  cent  chloropicrin 
and  20  per  cent  stannic  chloride  (so-called  N.  C).  This  mix- 
ture combines  the  advantages  of  a  gas  shell  with  those  of  a 
smoke  shell,  since  tlie  percentage  of  stannic  chloride  is  suffi- 


CHLOROPICRIN  149 

ciently  high  to  form  a  very  good  cloud.  In  addition  to  this, 
it  is  believed  that  the  presence  of  the  chloride  increases  the 
rate  of  evaporation  of  the  chloropicrin.  It  has  been  claimed 
that  the  chloride  decreases  the  amount  of  decomposition  of 
the  chloropicrin  upon  the  bursting  of  the  shell,  but  careful 
experiments  appear  to  show  that  this  decomposition  is  neg- 
ligible and  that  the  stannic  chloride  plays  no  part  in  it.  This 
mixture  was  being  abandoned  at  the  close  of  the  war. 

This  N.  C.  mixture  has  also  been  used  in  Liven 's  projectors 
and  in  hand  grenades.  The  material  is  particularly  fitted  for 
hand  grenades,  owing  to  the  low  vapor  pressure  of  the  chloro- 
picrin, and  the  consequent  absence  of  pressures  even  on  warm 
days.  As  a  matter  of  fact,  it  was  the  only  filling  used  for  this 
purpose,  though  later  the  stannic  chloride  was  changed,  owing 
to  the  shortage  of  tin,  to  a  mixture  of  silicon  and  titanium 
chlorides. 

While  chloropicrin  is  sufficiently  volatile  to  keep  the  strata 
of  air  above  it  thoroughly  poisonous,  it  is  still  persistent  enough 
to  be  dangerous  after  five  or  six  hours. 


CHAPTER   IX 

DICHLOROETHYLSULFIDE 

''MUSTARD    GAS" 

The  early  idea  of  gas  warfare  was  that  a  material,  to  be 
of  value  as  a  war  gas,  should  have  a  relatively  high  vapor 
pressure.  This  would,  of  course,  provide  a  concentration  suffi- 
ciently high  to  cause  casualties  through  inhalation  of  the  gas- 
ladened  air.  The  introduction  of  ''mustard  gas"  (dichloro- 
ethylsulfide)  was  probably  the  greatest  single  development  of 
gas  warfare,  in  that  it  marked  a  departure  from  this  early 
idea,  for  mustard  gas  is  a  liquid  boiling  at  about  220°  C, 
and  having  a  very  low  vapor  pressure.  But  mustard  gas  has, 
in  addition,  a  characteristic  property  which,  combined  with 
its  high  persistency,  makes  it  the  most  valuable  war  gas  known 
at  the  present  time.  This  peculiar  property  is  its  blistering 
effect  upon  the  skin.  Very  low  concentrations  of  vapor  are 
capable  of  "burning"  the  skin  and  of  producing  casualties 
which  require  from  three  weeks  to  three  months  for  recovery. 
The  combination  of  these  properties  removed  the  necessity  for 
a  surprise  attack,  or  the  building  up  of  a  high  concentration 
in  the  first  few  bursts  of  fire.  A  few  shell,  fired  over  a  given 
area,  were  sufficient  to  produce  casualties  hours  and  even  days 
afterwards. 

Mustard  gas,  chemically,  is  dichloroethysulfide  (ClCHgCHg)  gS. 
The  name  originated  with  the  British  Tommy  because  the  crude 
material  first  used  by  the  Germans  was  suggestive  of  mustard 
or  garlic.  Various  other  names  were  given  the  compound, 
such  as  "Yellow  Cross,"  from  the  shell  markings  of  the  Ger- 
mans; "Yperite,"  a  name  used  by  the  French,  because  the 
compound  was  first  used  at  Ypres;  and  "blistering  gas," 
because  of  its  peculiar  effect  upon  the  skin. 

150 


MUSTARD  GAS"  151 


Historical 


It  seems  probable  that  an  impure  form  of  mustard  gas  was 
obtained  by  Richie  (1854)  by  the  action  of  chlorine  upon 
ethyl  sulfide.  The  substance  was  first  described  by  Guthrie 
(1860),  who  recognized  its  peculiar  and  powerful  physiological 
effects.  It  is  interesting  in  this  connection  to  note  that  Guthrie 
studied  the  effect  of  ethylene  upon  the  sulfur  chlorides,  since 
this  reaction  was  the  basis  of  the  method  finally  adopted  by 
the  Allies. 

The  first  careful  investigation  of  mustard  gas,  which  was 
then  only  known  as  dichloroethylsulfide,  was  carried  out  by 
Victor  Meyer  (1886).  Meyer  used  the  reaction  between  ethyl- 
ene chlorhydrin  and  sodium  sulfide,  with  the  subsequent 
treatment  with  hydrochloric  acid.  All  the  German  mustard 
gas  used  during  1917  and  1918  was  apparently  made  by  the 
use  of  these  reactions,  and  all  the  early  experimental  work 
of  the  Allies  was  in  this  direction. 

Mustard  gas  was  first  used  as  an  offensive  agent  by  the 
Germans  on  July  12-13,  1917,  at  Ypres.  According  to  an  English 
report,  the  physiological  properties  of  mustard  gas  had  been 
tested  by  them  during  the  summer  of  1916.  The  Anti-Gas 
Department  put  forward  the  suggestion  that  it  should  be  used 
for  chemical  warfare,  but  at  that  time  its  adoption  was  not 
approved.  This  fact  enabled  the  English  to  quickly  and  cor- 
ctly  identify  the  contents  of  the  first  Yellow  Cross  dud 
"eceived.  It  is  not  true,  as  reported  by  the  Germans,  that  the 
material  was  first  diagnosed  as  diethylsulfide. 
^^  The  tactical  value  of  mustard  gas  was  immediately  recog- 
^Hzed  by  the  Germans  and  they  used  tremendous  quantities 
^H  it.  During  ten  days  of  the  Fall  of  1917,  it  is  calculated  that 
^Bver  1,000,000  shell  were  fired,  containing  about  2,500  tons  of 
^^ustard  gas.     Zanetti  states  that  the  British  gas  casualties 

f'^nring  the  month  following  the  introduction  of  mustard  gas 
re  almost  as  numerous  as  all  gas  casualties  incurred  during 
i  previous  years  of  the  war.  Pope  says  that  the  effects  of 
istard  gas  as  a  military  weapon  were  indeed  so  de«b|ting 
it  by  the  early  autumn  of  1917  the  technical  advisers  of  the 


152  CHEMICAL  WARFARE 

upon   large   scale   installations   for   the   manufacture   of  this 
material. 

Preparation  and  Manufacture 

The  analysis  of  the  first  German  shell  indicated  that  the 
mustard  gas  contained  therein  had  been  prepared  by  the 
method  published  by  Victor  Meyer  (1886)  and  later  used  by 
Clark  (1912)  in  England.  It  was  natural,  therefore,  that  atten- 
tion should  be  turned  to  the  large  scale  operation  of  this 
method. 

The  following  operations  are  involved:  Ethylene  is  pre- 
pared by  the  dehydration  of  ethyl  alcohol.  The  interaction  of 
hypochlorous  acid  (HCIO)  and  ethylene  yields  ethylene 
chlorhyd  in,  ClCHsCH^OH.  When  this  is  treated  with  sodium 
sulfide,  dihydroxyethyl  sulfide  forms,  which,  heated  with 
hydrochloric  acid,  yields  dichloroethyl  sulfide.  Chemically,  the 
reactions  may  be  written  as  follows: 

CH3CH20H  =  CH2  :  CH2+H2O 
CH2  :  CH2H-HC10  =  H0CH2CH,C1 
2HOCH2CH2Cl+Na2S  =  (HOCH2CH2)2S+2NaCl 
(H0CH2CH2)2S-|-2HC1=  (C1CH2CH2)2S+2H20 

Without  going  into  the  chemistry  of  this  reaction,  which 
is  thoroughly  discussed  by  Gomberg^  (see  also  German  Manu- 
facture), it  may  be  said  that  this  **  procedure  proved  to  be 
unsuitable  for  large  scale  production"  (Dorsey).  As  Pope 
remarks,  ''That  he  (the  German)  should  have  been  able  to 
produce  three  hundred  tons  of  mustard  gas  per  month  by 
the  large  scale  installation  of  the  purely  academic  method  (of 
Meyer)  constitutes  indeed  'a  significant  tribute  to  the  poten- 
tialities represented  by  the  large  German  fine  chemical  fac- 
tories.' "  It  is  true  that  a  gjreat  deal  of  experimental  work 
was  carried  out  by  the  Allies  on  this  method,  but  further  study 
was  dropped  as  soon  as  the  Pope  method  was  discovered. 

The  first  step  in  advance  in  the  manufacture  of  mustard  gas 
was  the  discovery  that  ethylene  would  react  with  sulfur  dichlor- 
ide.    While  American  chemists  were  not  very  successful  in  their 

^J.  Am.  Chem.  Soc.  41,  14]4  (1919). 


''MUSTARD  GAS"  153 

application  of  this  reaction,  either  in  the  laboratory  or  the  plant, 
it  was  apparently,  according  to  Zanetti,  the  only  method  used  by 
the  French  (the  only  one  of  the  Allies  that  manufactured  and 
fired  mustard  gas).  The  plant  was  that  of  the  Societe  Chimique 
des  Usines  du  Rhone  and  was  started  early  in  March,  1918,  with 
a  production  of  two  to  three  tons  a  day.  In  July  it  was  pro- 
ducing close  to  twenty  tons  a  day.  The  plant  was  being  dupli- 
cated at  the  time  of  the  Armistice,  so  that  probably  in  December, 
1918,  the  production  of  mustard  gas  by  the  dichloride  process 
would  have  reached  about  40  tons.  Zanetti  points  out,  however, 
that  the  process  involved  complicated  and  costly  apparatus  and 
required  considerable  quantities  of  carbon  tetrachloride  as  a 
solvent.  It  is  for  this  reason  that  the  Levinstein  process  would 
have  been  a  tremendous  gain,  had  the  war  continued. 

About  the  end  of  January,  1918,  Pope  and  Gibson,  in  a 
study  of  the  reaction  originally  used  by  Guthrie,  found  that 
the  action  of  ethylene  upon  sulfur  chloride  (SgClg)  at  60°. 
yielded  mustard  gas  and  sulfur: 

2CH2  :  CH24-S2Cl2  =  (CH2ClCH2)2S-fS 

The  reaction  at  this  temperature  caused  the  separation  of 
sulfur;  this  occurred  after  the  product  stood  for  some  time 
or  immediately  if  it  was  treated  with  moist  ammonia  gas. 
While  this  process  was  put  into  commercial  operation,  both  in 
England  and  America,  it  offered  considerable  difficulty  from 
an  operating  standpoint.  The  sulfur  would  often  separate  out 
and  block  the  inlet  tubes  (ethylene).  While  it  is  comparatively 
easy  to  remove  the  mustard  gas  from  the  separated  sulfur  by 
decantation,  a  certain  amount  always  remains  with  tlie  sulfur. 
It  is  almost  impossible  to  economically  remove  this,  and  its 
presence  adds  to  the  difficulty  of  removing  the  sulfur  from  the 
reactors;  the  men  engaged  in  this  operation  almost  always 
become  casualties.  •'* 

It  was  especially  important,  therefore,  when  Green  dis- 
covered that,  if  the  reaction  was  carried  out  at  30°,  the  sulfur 
did  not  settle  out  but  remained  in  **pseudo  solution"  in  the 
mustard  gas  (Pope)  or  as  a  loose  chemical  combination  of 
the  monosulfide  (mustard  gas)  with  an  atom  of  sulfur  (Green). 
This  material  has  all  the  physiological  activity  of  the  pure 


154 


CHEMICAL  WARFARE 


monosulfide,  while  the  enormous  technical  difficulties  of 
handling  separated  sulfur  are  entirely  obviated  by  this  method 
of  manufacture.     To  carry  out  the  reaction  Levinstein,  Ltd., 


f '"' 

.  u  , -r- — ' ' 

' 

i|  ;f4W|'VfMi::iiii 

i       1  < 

II!            1 

Li  .           -Si       ! 

Fig.  29. — Th€  Levinstein  Reactor  as  Installed  at  Edgewood  Arsenal. 

devised  the  Levinstein  ''reactor."  The  apparatus  is  shown  in 
Fig.  29.  The  process  consists  essentially  in  bringing  together 
sulfur  chloride  and  very  pure  ethylene  gas  in  the  presence  of 
crude   mustard  gas   as  a  solvent   at  a  temperature  ranging 


''MUSTARD  GAS''  155 

Ijetween  30-35°  C.  A  supply  of  unchanged  monochloride  is 
constantly  maintained  in  the  reacting  liquid  until  a  sufficiently 
large  batch  is  built  up.  Then  the  sulfur  monochloride  feed 
is  discontinued  and  the  ethylene  feed  continued  until  further 
absorption  ceases.  By  controlling  the  ratio  of  mustard  gas 
to  uncombined  monochloride,  the  reaction  velocity  is  so 
increased  that  the  lower  temperature  may  be  used. 

The  product  thus  obtained  is  a  pale  yellow  liquid  which 
deposits  no  sulfur  and  requires  no  further  treatment.  It  is 
ready  for  the  shell-filling  plant  at  once.  The  obvious  advantage 
of  this  method  led  to  its  adoption  in  all  American  plants  started 
for  the  manufacture  of  mustard  gas  (Edgewood,  Cleveland 
and  Buffalo). 


Ethylene 

\ 

It  was  known  from  the  work  of  certain  French  chemists 
that  in  the  presence  of  such  a  catalyst  as  kaolin,  ethyl  alcohol 
is  dehydrated  at  an  elevated  temperature  to  ethylene.  The 
process  as  finally  developed  by  American  chemists  consisted 
essentially  in  introducing  mixtures  of  alcohol  vapor  and  steam, 
in  the  ratio  of  one  to  one  by  weight,  into  an  8-inch  iron  tube 
with  a  3-inch  core,  in  contact  with  clay  at  500-600°  C.  The 
use  of  steam  rendered  the  temperature  control  more  uniform 
and  thus  each  unit  had  a  greater  capacity  of  a  higher  grade 
product.  The  gaseous  products  were  removed  through  a  water- 
cooled  surface  condenser.  One  unit  of  this  type  had  a  demon- 
strated capacity  of  400  cubic  feet  per  hour  of  ethylene,  between 
92  and  95  per  cent  pure,  while  the  conversion  efficiency  (alcohol 
to  ethylene)  was  about  85  per  cent.  The  Edgewood  plant 
consisted  of  40  sueh  units.  This  would  have  yielded  sufficient 
ethylene  to  make  40  tons  of  mustard  gas  per  24-hour  day. 

The  English  procedure  consisted  in  the  use  of  phosphoric 
acid,  absorbed  onto  coke.  An  American  furnace  was  designed 
and  built  which  gave  2,000  cubic  feet  per  hour  of  ethylene, 
with  a  purity  of  98  to  99  per  cent.  This  furnace  was  not  used 
on  a  large  scale,  because  of  the  satisfactory  nature  of  the 
kaolin  furnaces. 


156 


CHEMICAL  WARFARE 


WW 


c^^ 


o 


MUSTARD  GAS" 


157 


Sulfur  Chloride 


Since  chlorine  was  prepared  at  Edgewood,  it  was  logical 
that  some  of  this  chlorine  should  be  utilized  in  the  preparation 
of  sulfur  chloride.  The  plant  constructed  consisted  of  30  tanks 
(78  inches  in  diameter  and  35  feet  long),  each  capable  of 


Fig.  31. — Row  of  Furnaces  for  the  Preparation  of  Ethylene. 


producing  20,000  pounds  of  monochloride  per  day.  The  tanks 
are  partially  filled  with  sulfur  and  chlorine  passed  in.  The 
reaction  proceeds  rapidly  with  sufficient  heat  to  keep  the  sulfur 
in  a  molten  condition.  If  the  chlorine  is  passed  in  too  rapidly, 
the  heat  generated  may  be  sufficient  to  boil  off  the  sulfur 
chloride  formed.  Hence  water  pipes  are  provided  so  that  a 
supply  of  cold  water  may  be  sprayed  upon  the  tanks,  keeping 
the  temperature  within  the  proper  limits. 

In  the  manufacture  of  one  ton  of  mustard  gas,  about  one 


158 


CHEMICAL  WARFARE 


ton  of  sulfur  chloride  and  a  little  less  than  half  a  ton  of 
ethylene  (12,640  cubic  feet)  are  required. 

German  Method  op  Manufacture* 


"Preparation  of  Ethylene — The  gas  was  prepared  by  passing 
alcohol  vapor  over  aluminum  oxide  at  a  temperature  of  380°  to  400°. 
The  details  of  the  construction  of  one  of  the  furnaces  are  given  in 
Figs.  32  and  33.  The  furnaces  were  very  small  and  sixty  units  were 
needed  to  furnish  the  amount  of  gas  required.  The  tubes  containing 
the  catalyzer  were  made  of  copper  and  were  heated  in  a  bath  of  molten 


Outlet  of  Ethylene  Mixture 


Heating  Gas  Outlet 


10  Flue  Pipe 


A^Back  PresBure  EeHef 


3Q^ 


Cooling  H2O 

3t 


GondeDser  Coil 


Inlet  Pipe 

Alcohol  Vapor 

Inlet  Pi 


2-> 
Steam  Jactet  Plpe-> 


AX^Condensed 
Alcohol  Outlet 


Fig.  32. 


-Preparation  of  Ethylene  at  Badische  Anilin  und  Soda  Fabrik. 
60  units. 


potassium  nitrate.  It  was  stated  that  the  catalyzer  was  made  according 
to  the  directions  of  Ipatieff,  and  that  its  life  was  from  10  to  20  days. 
The  gas  produced  was  washed  in  the  usual  form  of  scrubber.  The 
yield  of  ethylene  was  stated  to  be  about  90  per  cent  of  the  theoretical. 
"Preparation  of  Ethylene  Chlorhydrin — The  reaction  was  car- 
ried out  in  a  cylindrical  tank  resting  on  its  side.  The  tank  was 
furnished  with  a  stirrer  and  was  insulated  by  means  of  cork  in  order 
to  prevent  the  transfer  of  heat  from  the  atmosphere  to  the  inside. 
Enough  chloride  of  lime  was  introduced  into  the  tank  to  furnish  500 
kg.  of  available  chlorine,  together  with  5  cu.  m.  of  water.  At  first, 
about  20  cu.  m.  of  carbon  dioxide  were  led  into  the  mixture,  next 
ethylene,  and  later  carbon  dioxide  and  ethylene  simultaneously.     The 

*  Norris,  J.  Ind.  Eng.  Chem.,  11,  821  (Sept.,  1919). 


''MUSTARD  GAS' 


159 


rate  of  absorption  of  ethylene  was  noted  and  when  it  slackened,  more 
carbon  dioxide  was  added.  Fuller  details  as  to  the  addition  of  the 
two  gases  were  not  given  as  it  was  stated  that  it  was  a  matter  of 


Heating  Gas 
Outlet 

k 

J- 

p 

•<: 

3 

•'-lo'Vlue 

^ 

"L"\ 

N-^ 

Ua 

^    ^    ^    A 

A 

— fc- 

\. 

C5 

I     I 

Jk,       ) 

J 

\ 

Alcohol  Vapor  Inlot  Fipoi 

)/ 

KN03^ 
Contact 


Etbyleue  i:ixturo  Ootlct 


1  Copper  Coil 
12  Turus 


Cotl  enters  Contact' 
Tube  at  Base 


Fig.  33. — Ethvlene  Production  at  Badische  Anilin  imd  Soda  Fabrik.      1  unit. 


judgment  on  the  part  of  the  workman  who  was  carrying  out  the 
operation.  The  reaction  should  be  carried  out  at  as  low  a  temperature 
as  possible,  but  it  was  found  impossible  to  work  below  5°  with  the 

Stbylene  Gaa  Inlet 
CO,Inlet 


^lixing  Blades 
Lead  Lined 
Cotl 


Fump 

To  Colli 

® ) )     and  Filter 

Press 


Fig.  34. — Chlorhydrin  reaction  kettle  at  Badische  Anilin  und  Soda  Fabiik. 

16  units. 

apparatus  employed  in  this  factory.  The  temperature  during  the 
reaction  varied  between  5°  and  10°.  In  order  to  maintain  this  tem- 
perature, the  solution  was  constantly  pumped  from  the  apparatus 
through  a  coil  which  was  cooled  by  brine.    When  ethylene  was  no  longer 


160 


CHEMICAL  WARFARE 


absorbed  and  tbere  was  an  excess  of  carbon  dioxide  present,  the  solution 
was  tested  for  hypochlorous  acid.  The  time  required  for  the  introduc- 
tion of  ethylene  was  between  2  and  3  hrs. 

"The  contents  of  the  apparatus  were  passed  through  a  filter  press 
by  means  of  which  the  calcium  carbonate  was  removed.  The  solution 
thus  obtained  contained  from  10  to  12  per  cent  of  ethylene  chlorhydrin. 


©01^ 


Fig.  35. — Mustard  Gas  Manufacture  at  Leverkusen.     Layout  for  Chlorina- 
tion  of  Thiodiglycol. 


It  was  next  distilled  with  steam  and  a  distillate  collected  which  contained 
between  18  and  20  per  cent  of  chlorhydrin.  The  yield  of  chlorhydrin 
was  from  60  to  80  per  cent  of  that  calculated  from  the  ethylene  used. 
"Preparation  of  Dihydroxyethylsulfide — To  prepare  the  hy- 
droxysulfide,  the  theoretical  quantity  of  sodium  sulfide,  either  in  the  form 
of  the  anhydrous  salt  or  as  crystals,  was  added  to  the  18  to  20  per 
cent  solution  of  chlorhydrin.     After  the  addition   of  the  sulfide,  the 


"MUSTARD  GAS"  161 

mixture  was  heated  to  about  90°  to  100°.  It  was  then  pumped  to  an 
evaporator,  and  heated  until  all  the  water  was  driven  off.  The  glycol 
was  next  filtered  from  the  salt  which  separated,  and  distilled  in  a 
vacuum.  The  yield  of  glycol  was  about  90  per  cent  of  the  theoretical, 
calculated  from  the  chlorhydrin. 

"Preparation  of  Dichlorethylsulfide — The  thiodiglycol  was 
taken  from  the  rail  to  two  large  storage  tanks  and  thence  drawn  by 
vacuum  direct  to  the  reaction  vessel.  Each  reaction  vessel  was  placed 
in  a  separate  cubicle  ventilated  both  from  above  and  below  and  fitted 
with  glass  windows  for  inspection.  The  vessels  themselves  were  made 
of  ll^  in.  cast  iron  and  lined  with  10  mm.  lead.  They  were  2.5  m. 
high  and  2.8  m.  in  diameter.  These  tanks  were  jacketed  so  that  they 
could  be  heated  by  water  and  steam,  and  the  reaction  was  carried 
out  at  50°.  The  hydrochloric  acid  coming  from  the  main  pipe  was 
passed  through  sulfuric  acid  so  that  the  rate  could  be  observed,  and 
passed  in  by  means  of  12  glass  tubes  of  about  2  cm.  diameter.  The 
rate  of  flow  was  maintained  at  as  high  a  rate  as  possible  to  procure 
absorption.  The  vapors  from  the  reaction  were  led  from  the  vessel 
through  a  pipe  into  a  collecting  room,  and  then  through  a  scrubber 
containing  charcoal  and  water,  through  a  separator,  and  then,  finally, 
into  the  chimney.  These  exhaust  gases  were  drawn  off  by  means  of  a 
fan  which  was  also  connected  with  the  lower  part  of  the  chamber 
in  which  the  reaction  vessels  were  set,  so  that  all  the  gases  had  to 
pass  through  the  scrubber  before  going  to  the  chimney.  When  the 
reaction  was  completed,  the  oil  was  removed  by  means  of  a  vacuum, 
induced  by  a  water  pump,  into  a  cast-iron  washing  vessel. 

"The  hydrochloric  acid  layer  was  removed  to  a  stoneware  receiver, 
also  by  vacuum.  A  glass  enabled  the  operator  to  avoid  drawing  oil 
over  with  the  acid.  The  pan  was  fitted  with  a  thermometer  to  the  interior 
as  well  as  to  the  jacket.  For  testing  the  material  during  reaction, 
provision  was  made  for  drawing  some  up  by  vacuum  to  a  hydrometer 
contained  in  a  glass  funnel.  The  final  test  at  this  point  read  126°  Tw. 
Another  portion  could  be  drawn  up  to  a  test  glass  and  hydrochloric 
acid  passed  through  it  in  full  view.  A  float  contained  in  a  glass  outer 
tube  served  to  show  the  level  of  the  liquid  in  tlie  vessel.  The  pans 
in  which  the  operation  is  carried  on,  as  well  as  those  employed  for 
washing  and  distilling  the  product,  were  of  a  standard  pattern  employed 
in  many  other  operations  in  the  works. 

"The  washer  consisted  of  a  cast-iron  vessel,  lead  lined,  and  was  2.5 
m.  in  diameter,  2  m.  deep,  and  fitted  with  a  dome  cover  and  stirring 
gear.  Lead  pipes  served  for  the  introduction  of  sodium  carbonate 
solution  and  water.     Similar  pipes  were  fitted  for  drawing  these  off 


162  CHEMICAL  WARFARE 

by  means  of  a  vacuum.  A  manhole  on  the  cover,  with  a  flat  top,  was 
fitted  with  light  and  sight  glasses  to  which  were  fitted  a  small  steam 
coil  for  keeping  them  clear.  The  washed  oil  is  drawn  off  to  a  distilla- 
tion still,  which  is  a  cast-iron  vessel  homogeneously  lead  coated,  1.5  m. 
in  diameter  and  2  m.  deep,  fitted  with  a  lead  heating  coil  and  connected 
through  a  spiral  lead  condenser  and  receiver  to  a  vacuum  pump.  The 
water  is  distilled  from  the  oil  at  a  pressure  of  from  62  to  70  mm. 
absolute  pressure.  When  dried,  the  oil  is  sent  by  vacuum  to  a  mixing 
vessel,  similar  in  most  respects  to  the  washing  vessel,  in  which  it  is 
mixed  with  an  appointed  quantity  of  solvent,  which,  in  this  factory, 
was  usually  chlorobenzene  but  occasionally  carbon  tetrachloride.  The 
relative  quantities  varied  with  the  time  of  year,  and  instructions  were 
sent  from  Berlin  on  this  point.  Thence  the  mixture  was  passed  to  a 
storage  tank  and  into  tank  wagons." 


American  Method  of  Manufacture 

The  Chemical  Warfare  Service  investigated  carefully  the 
three  methods  (German,  French,  and  English)  and  finally 
adopted  the  Levinstein  process.  The  follov^ing  discussion  is 
taken  from  a  report  originally  made  during  construction, 
Sept.,  1918. 

The  Levinstein  reactor  consisted  of  a  jacketed  and  lead- 
lined  vessed  or  steel  tank,  8  feet  5  inches  in  diameter  and  14 
feet  tall.  The  reactor  contained  1,400  feet  of  lead  pipe  (out- 
side diameter  2%  inches),  made  up  into  five  coils,  giving  a  total 
cooling  surface  of  1,200  square  feet.  The  finished  charge  of 
such  a  reactor  is  12  tons. 

Ethylene  v^as  introduced  through  lead  injectors,  of  v^hich 
there  were  16,  each  suspended  from  its  own  opening  in  the  top 
and  hanging  so  that  the  end  of  the  injector  tube  was  12  inches 
from  the  bottom  of  the  reactor.  The  nozzle  of  the  injector 
was  3/16  inch  outside  diameter  and  ethylene  was  introduced 
through  it  at  40  pounds  pressure. 

In  starting  the  reaction,  enough  sulfur  chloride  was  intro- 
duced into  the  reactor  to  cover  the  central  nozzles.  Ethylene 
was  now  introduced,  and  as  the  reaction  proceeded  sulfur  chlo- 
ride was  added  in  sufficient  quantities  to  give  a  high  rate  of 
reaction.     Brine  or  cold  water  was  introduced  through  the 


''MUSTARD  GAS"  163 

cooling  coils  and  jacket  to  keep  the  reacting  temperature 
at  35°  C. 

When  the  charge  was  completed,  the  ethylene  was  turned 
off  so  that  only  a  small  amount  bubbled  through  the  nozzles 
and  the  charge  syphoned  off  to  the  settling  tank.  f^These  were 
constructed  of  iron,  8  feet  in  diameter  and  19  feet  tall.  ;  They 
were  provided  with  iron  coils  by  which  the  liquid  may  be  cooled 
down,  or  the  sulfur,  which  precipitates  in  the  bottom,  melted. 
The  tank  was  large  enough  to  hold  six  complete  charges  of 
mustard  gas  and  all  the  sulfur  from  these  charges  was  allowed 
to  accumulate  before  removal  of  the  sulfur.  *  The  supernatant 
mustard  gas  was  di-awn  off  from  above  this  sulfur  to  storage 
tanks. 

Among  the  factors  which  influence  the  reaction  are  the 
following : 

A  temperature  of  over  60°  C.  in  lead  will  decompose  the 
product  slowly  when  sulfur  chloride  is  present. 

The  presence  of  iron  decomposes  the  product  rapidly  at  a 
temperature  of  50°  C.  and  probably  at  a  considerably  lower 
temperature. 

The  purity  of  the  product  is  dependent  upon  the  time  of 
reaction.  There  is  always  a  slow  reaction  between  the  mustard 
gas  and  sulfur  chloride,  and  because  of  this  the  charge  should 
be  completed  in  8  hours. 

In  general  the  more  sulfur  that  comes  out  of  the  solution, 
the  better  is  the  product.  Temperature  has  a  marked  effect 
on  the  separation  of  sulfur.  In  order  to  entirely  remove  the 
sulfur  from  the  product  it  was  the  custom  to  increase  the  tem- 
perature at  the  close  of  the  reaction  from  55°  to  70°  C.  This, 
liowever,  caused  plugging  of  the  lines  and  the  reactor. 

Properties 

Dichloroethylsulfide  (mustard  gas)  is  a  colorless,  oily 
liquid,  which  has  a  faint  mustard  odor.  The  pure  material  is 
said  to  have  an  odor  very  suggestive  of  that  of  water  cress. 
While  the  odor  is  more  or  less  characteristic,  it  is  possible  to 
have  extremely  dangerous  amounts  of  the  gas  in  a  neighbor- 
hood without  being  detected  through  its  odors.    It  still  seems 


164 


CHEMICAL  WARFARE 


to  be  an  open  question  whether  mustard  gas  paralyzes  the  sense 
of  smell.    One  can  find  opinions  on  both  sides. 

Mustard  gas  boils  at  215°-217°  C.  at  atmospheric  pressure, 
so  that  it  is  at  once  seen  to  be  a  very  persistent  gas.  It  distills 
without  decomposition  at  this  temperature  but  is  best  purified 
by  vacuum  distillation,  or  by  distillation  with  steam.  A  still 
for  the  vacuum  distillation  of  mustard  gas  has  been  described 
by  Streeter.* 

Mustard  gas  melts,  when  pure,  at  13°  to  14°  C.  (The 
ordinary  summer  temperature  is  20°-25°  C).  The  ordinary 
product,  as  obtained  from  the  *' reactor,''  melts  from  9°-10°  C. 
In  order  that  the  product  in  the  shell  might  be  liquid  at 
all  temperatures,  winter  as  well  as  summer,  the  Germans  added 
from  10  to  30  per  cent  of  chlorobenzene,  later  using  a  mixture 
of  chlorobenzene  and  nitrobenzene  and  still  later  pure  nitro- 
benzene. Carbon  tetrachloride  has  also  been  used  as  a  means 
of  lowering  the  melting  point.  Many  other  mixtures,  such 
as  chloropicrin,  hydrocyanic  acid,  bromoacetone,  etc.,  were 
tested,  but  were  not  used.  The  effect  on  the  melting  point  of 
mustard  gas  is  shown  in  the  folowing  table: 


Melting-point  of 

Mustard  gas  Mixt 

URES 

Per  Cent 
Added 

Cliloropicrin 

Chlorobenzene 

Carbon 
Tetrachloride 

0 
10 
20 
30 

13.4°  C. 
9.8 
6.3 
2.6 

13.4°  C. 

8.4 

6.4 

-1.0 

13.4°  C. 
9.8 
6  6 
3.1 

The  mustard  gas  as  finally  made  by  the  United  States 
contained  about  17  to  18  per  cent  sulfur  in  solution.  The  gas 
was  then  put  in  shell  and  fired  without  the  addition  of  any 
solvent.  In  actual  practice  this  impure  product  seemed  even 
more  powerful  in  causing  casualties  than  equal  quantities  of 
the  pure  mustard  gas.  Accordingly  no  redistilling  as  originally 
contemplated  was  actually  carried  out. 

*  J.  Ind.  Eng.  Chem.,  11,  292  (1919). 


''MUSTARD  GAS"  165 

The  specific  gravity  of  mustard  gas  at  20°  is  1.2741.  The 
solid  material  has  a  slightly  higher  value,  being  1.338  at  13°. 
Its  vapor  pressure  at  room  temperature  is  very  low;  at  20° 
this  value  has  been  found  to  be  about  0.06  mm.  of  mercury. 

Mustard  gas  is  practically  insoluble  in  water,  less  than 
0.1  per  cent  forming  a  saturated  solution.  The  reports  that  a 
1  per  cent  solution  could  be  obtained  did  not  consider  the 
question  of  hydrolysis.  Mustard  gas  is  freely  soluble  in  all 
the  ordinary  organic  solvents,  such  as  ligroin,  alcohol,  ether, 
chloroform,  acetic  acid,  chlorobenzene,  etc.  In  case  the  solvent 
is  miscible  with  water,  dilution  throws  out  the  product  as 
an  oil. 

Chemical  Properties 

Mustard  gas  is  very  slowly  decomposed  by  water,  owing 
to  its  very  slight  solubility.  The  products  are  dihydroxyethyl- 
sulfide  and  hydrochloric  acid : 

(C1GH2CH2)2S+2H20  =  (H0CH2CH2)2S+2HC1 

Certain  sulfonated  oils  accelerate  the  rate  of  hydrolysis,  both 
by  increasing  the  rate  ol  solution  and  the  solubility  of  the 
mustard  gas.  Alkalies  also  increase  the  rate  of  hydrolysis. 
Oxidizing  agents  destroy  mustard  gas.  This  reaction  was  made 
use  of  practically  in  that  solid  bleaching  powder  was  early 
introduced  as  a  means  of  destroying  mustard  gas  in  the  field. 
(Pig.  9.) 

Chlorinating  agents  (chlorine,  sulfur  dichloride,  etc.) 
rapidly  transform  mustard  gas  into  an  inactive  (non-blistering) 
substance.  Sulfur  dichloride  was  a  valuable  reagent  in  both 
laboratory  and  works  in  '* cleaning  up"  mustard  gas.  This 
reaction  also  explains  why  the  early  attempts  to  prepare  mus- 
tard gas  by  the  interaction  of  ethylene  and  sulfur  dichloride 
were  unsuccessful.  Mustard  gas  is  probably  formed,  but  is 
almost  immediately  chlorinated  by  the  excess  of  sulfur  dichlo- 
ride. Sulfur  chloride  on  the  other  hand  has  no  effect  on  mus- 
tard gas.  Chloramine-T  and  Dichloramine-T  (the  valuable  thera- 
peutic agents  introduced  by  Dakin  and  Carrel  for  treatment 
of  wounds)   also  react  with  mustard  gas.     For  this  reason 


166 


CHEMICAL  WARFARE 


they  were  advocated  as  treatment  for  mustard  gas  burns.    But 
as  we  will  see  later,  they  were  not  altogether  successful. 


V 


Detection 


At  first  the  only  method  of  detecting  mustard  gas  was 
through  the  sense  of  smell.  It  was  then  believed  that  concen- 
trations which  could  not  be  detected  in  this  way  were  harm- 
less. Later  this  proved  not  to  be  the  case,  and  more  delicate 
methods  had  to  be  devised.  In  the  laboratory  and  in  the  field 
these  tests  were  not  very  satisfactory,  because  most  of  them 
depended  upon  the  presence  of  chlorine,  and  the  majority  of 


To  Gas  Tank 


Fig.  36. — Field  Detector  for  Mustard  Gas. 

the  war  gases  contained  chlorine  or  one  of  the  other  halogens. 
The  Lantern  Test  depended  upon  the  accumulation  of  the 
halogen  upon  a  copper  gauze  and  the  subsequent  heating  of 
the  gauze  in  a  Bunsen  flame.  This  test  could  be  made  to  detect 
one  part  of  mustard  gas  in  ten  million  parts  of  air.  Another 
field  detector  devised  by  the  Chemical  Warfare  Service  con- 
sisted in  the  use  of  selenious  acid.  Here  again  the  lack  of 
specificity  is  apparent,  for  while  certain  halogen  compounds 
did  not  give  the  test,  arsine  and  organic  arsenicals  gave  a  posi- 
tive reaction  and  often  in  a  shorter  time  than  mustard  gas. 

The  Germans  are  said  to  have  had  plates  covered  with  a 
yellow  composition  which  had  the  property  of  turning  black 
in  the  presence  of  mustard  gas.     These  plates  were  lowered 


"MUSTARD  GAS''  167 

ito  the  bottom  of  recently  captured  trenches  and  if,  after  a 
Few  minutes,  they  turned  black,  the  presence  of  mustard  gas 
-as  suspected.  It  is  also  stated  that  the  characteristic  yellow 
^aint  on  the  ogive  of  the  mustard  gas  shell  had  the  same  com- 
position, and  was  useful  in  detecting  leaky  shell.  According 
to  a  deserter's  statement,  however,  reliance  upon  this  test 
resulted  in  casualties  in  several  instances. 

A  white  paint  has  also  been  reported  which  turned  red 
in  the  presence  of  mustard  gas.  This  color  change  was  not 
characteristic,  for  tests  made  by  our  Army  showed  that  other 
oils  (aniline,  turpentine,  linseed)  were  found  to  produce  the 
same  effect. 

The  Chemical  Warfare  Service  was  able  to  develop  an 
enamel  and  an  oil  paint  which  were  very  sensitive  detectors 
of  mustard  gas.  Both  of  these  were  yellow  and  became  dark 
red  in  contact  with  mustard  gas.  The  change  was  practically 
instantaneous.  The  enamel  consisted  of  chrome  yellow  as  pig- 
ment mixed  with  oil  scarlet  and  another  dye,  and  a  lacquer 
vehicle,  which  is  essentially  a  solution  of  nitrocellulose  in  amyl 
acetate.  One  gallon  of  this  enamel  will  cover  946,500  sq.  cm., 
or  a  surface  equivalent  to  a  band  3  cm.  wide  on  12,500  seven 
cm.  shell. 

The  paint  was  composed  of  a  mixture  of  50  per  cent  raw 
linseed  oil  and  50  per  cent  Japan  drier,  with  the  above  dye 
mixture  added  to  the  required  consistency.  In  contact  with 
liquid  mustard  g^s,  this  changes  to  a  deep  crimson  in  4  seconds. 
Furthermore,  in  contact  with  arsenicals,  this  paint  changes 
to  a  color  varying  from  deep  purple  to  dark  green,  the  color 
change  being  almost  instantaneous  and  very  sensitive,  even  to 
the  vapors  of  these  compounds.  Other  substances  have  no  effect 
upon  the  paint. 

For  field  work,  however,  nothing  was  found  equal  to  the 
trained  nose,  and  it  is  questionable  if  any  of  the  mechanical 
means  described  will  be  used  in  the  field. 


> 


Physiological  Action 


One  of  the  most  interesting  phases  of  mustard  gas  is  its 
peculiar  physiological  action.     This  has  been  studied  exten- 


168 


CHEMICAL  WARFARE 


sively,  both  as  relates  to  the  toxicity  and  to  the  skin  or  blister- 
ing effect. 

/     Toxicity 

When  one  considers  the  high  boiling  point  of  mustard  gas, 
and  its  consequent  low  vapor  pressure,  he  is  likely  to  conclude 
that  such  a  substance  would  be  of  comparatively  little  value 
as  a  toxic  or  poison  gas.  While  it  is  true  that  an  important 
part  of  the  military  value  of  mustard  gas  has  been  because 
of  its  vesicant  properties,  the  fact  still  remains  that  it  is  one 
of  our  most  toxic  war  gases.  The  following  comparison  with 
a  few  of  the  other  gases  indicates  this: 


Mg.  per  Liter 


Mustard  gas 

Phosgene 

Hydrocyanic  acid 

Chloropicrin 

Chlorine 


Dogs 


0.05 

0.1 

0.8 
3  0 


When  an  animal  is  exposed  to  the  vapors  of  mustard  gas 
in  high  concentration,  it  subsequently  shows'  a  complexity  of 
symptoms,  which  may  be  divided  into  two  classes: 

(1)  The  local  effects  on  the  eyes,  skin  and  respiratory 
tract.  These  are  well  recognized  and  consist  mainly  of  con- 
junctivitis and  superficial  necrosis  of  the  cornea;  hyperemia, 
oedema  and  later,  necrosis  of  the  skin,  leading  to  a  skin  lesion 
of  great  chronicity;  and  congestion  and  necrosis  of  the 
epithelial  lining  of  the  trachea  and  bronchi. 

(2)  The  systemic  effects  due  to  the  absorption  of  the  sub- 
stance into  the  blood  stream,  and  its  distribution  to  the  various 
tissues  of  the  body. 

The  most  striking  observation  about  the  symptoms  of  mus- 
tard gas  poisoning  is  the  latent  period  which  elapses  after 
exposure  before  any  serious  objective  or  subjective  effects  are 


I 


''MUSTARD  GAS"  .  169 

oted.     The  developments  of  the  effects  are  then  quite  slow, 
unless  very  high  superlethal  doses  have  been  inhaled. 

At  first  it  was  a  very  serious  question  whether  or  not  the 
emporary  blindness  resulting  from  mustard  gas  would  not 
e  permanent.     Later,  as  the  depth  and  seriousness  of  some 
f  the  body  burns  became  well  known,  it  was  a  seven-day 
wonder  that  no  permanent  blindness  occurred. 

The  reason  seems  to  be  largely  a  mechanical  one.  The 
constant  winking  of  the  eyelids  apparently  washes  the  mustard 
gas  off  the  eyeball  and  carries  it  away  so  that  not  enough 
remains  to  burn  to  the  depth  necessary  to  cause  permanent 
blindness. 

Due  to  the  very  slight  concentrations  ordinarily  encountered 
in  the  field,  resulting  from  a  very  slow  rate  of  evaporation, 
the  death  rate  is  very  low,  probably  under  1  per  cent  among 
tlie  Americans  gassed  with  mustard  during  the  war. 

If,  on  the  other  hand,  the  gas  be  widely  and  very  finely 
dispersed  by  a  heavy  charge  of  explosive  in  the  shell,  the  gas 
is  very  deadly.  In  such  cases  the  injured  breathe  in  minute 
particles  of  the  liquid  and  thus  get  hundreds  of  times  the 
amount  of  gas  that  would  be  inhaled  as  vapor.  This  so-called 
''high  explosive  mustard  gas  shelP'  was  a  German  development 
in  the  very  last  months  of  the  war.  Its  effects  were  great 
enough  to  make  it  certain  that  in  the  future  large  numbers 
of  these  shell  will  be  used. 

The  similarity  of  the  symptoms  and  pathological  effects 
after  the  inhalation  of  large  amounts  of  the  vapor  and  those 
following  an  injection  of  an  olive  oil  or  water  solution  of 
mustard  gas  led  Marshall  and  his  associates  to  conclude  that 
in  high  concentrations  mustard  gas  is  absorbed  through  the 
lungs.  A  further  bit  of  evidence  consists  in  the  isolation  of 
the  hydrolysis  product,  dihydroxyethylsulfide,  in  the  urine  of 
animals  poisoned  by  inhalation  of  mustard  gas.  This  product 
is  not  toxic  and  is  not  responsible  for  the  effects  of  mustard 
gas.  Hydrochloric  acid,  however,  does  produce  very  definite 
effects  upon  the  animal  and  may  cause  death. 

From  these  facts  Marshall^  has  proposed  the  following 
mechanism  of  the  action  of  mustard  gas : 

^Marshall,  Lynch  and  Smith,  J.  Pharmacal,  12,  291-301    (1918). 


170  CHEMICAL  WARFARE 

"Dichlorethysulphide  is  very  slightly  soluble  in  water  and  very 
freely  soluble  in  organic  solvents,  or  has  a  high  lipoid  solubility  or 
partition  coefficient.  It  would,  therefore,  be  expected  to  penetrate 
cells  very  readily.  Its  rapid  powers  of  penetration  are  practically 
proven  by  its  effects  upon  the  skin.  Having  penetrated  within  the 
living  cell,  it  would  undoubtedly  hydrolyze.  The  liberation  of  free 
hydrochloric  acid  within  the  cell  would  produce  serious  effects  and 
might  account  for  the  actions  of  dichlorethylsulphide.  To  summarize, 
then,  the  mechanism  of  the  action  of  dichlorethysulphide  appears  to  be 
as  follows: 

"1.  Rapid  penetration  of  the  substance  into  the  cell  by  virtue  of 
its  high  lipoid  solubility. 

2.  Hydrolysis  by  the  water  within  the  cell,  to  form  hydrochloric 
acid  and  dihydroxyethylsulphide. 

3.  The  destructive  effect  of  hydrocliloric  acid  upon  some  part  or 
mechanism  of  the  cell. 

"Although  hydrochloric  acid  does  not  penetrate  cells  readily  and 
is  easily  neutralized  by  the  buffer  action  of  the  fluids  of  the  body, 
we  might  expect  by  flooding  the  body  with  large  quantities  of  acid 
to  produce  some  of  the  characteristic  effects  of  mustard  gas.  Stimula- 
tion of  the  respiratory  center  is  a  well  known  effect  of  acid.  Convul- 
sions and  salivation  may  be  produced  by  injection  of  hydrochloric  acid 
and  we  have  been  able  to  produce  slowing  of  the  heart  by  rapid 
injection  of  this  acid. 

"The  delayed  action  of  mustard  gas  might  be  explained  by  the 
formation  of  some  compound  with  some  constituent  of  the  blood. 
However,  blood  taken  from  dogs  which  had  been  poisoned  with  mustard 
gas  and  were  exhibiting  typical  symptoms  at  the  time,  injected  into 
normal  dogs  produced  no  effect.  Serum  treated  in  vitro  with  mustard 
gas  and  allowed  to  stand  and  then  injected  into  a  dog,  produced  no 
effect.  The  fluid  which  is  formed  in  the  vesicle  and  blebs  produced 
by  the  application  of  mustard  gas  to  the  skin  produces  no  mustard 
gas  effects." 

In  studying  the  toxicity  of  mustard  gas  for  dogs,  it  was 
observed  that  a  concentration  of  0.01  mg.  per  liter  could  be 
tolerated  indefinitely.  If  this  value  is  considered  as  a  threshold 
value,  and  subtracted  from  the  toxicity  values  for  varying 
periods  of  time,  it  is  found  that  there  is  a  definite  relation 
between  the  toxic  concentration  and  the  time  of  exposure. 
This  is  expressed  by  the  formula 

(C-0.01)f=K 


I 


''MUSTARD  GAS"  171 

where  c  is  the  concentration  observed  for  a  given  time  t. 
K  has  the  approximate  value  of  1.7,  where  t  varies  between  7.5 
and  480  minutes. 


Vesicant  Action 

In  addition  to  its  toxicity  mustard  gas  is  highly  important 
because  of  its  peculiar  irritating  effect  upon  the  skin.  Its 
value  is  seen  when  we  realize  that  one  part  in  14,000,000  is 
capable  of  causing  conjunctivitis  of  the  eye  and  that  one  part 
in  3,000,000  and  possibly  one  part  in  5,000,000  will  cause  a 
skin  burn  in  a  sensitive  person  on  prolonged  exposure.  Accord- 
ing to  Warthin,  the  lesions  produced  by  mustard  gas  are  those 
of  a  chemical,  not  unlike  hydrochloric  acid,  but  of  much 
greater  intensity.  The  pathology  of  these  lesions  has  been  care- 
fully studied  and  fully  described  by  Warthin  and  Weller  in 
their  book  on  The  Pathology  of  Mustard  Gas.  Our  observa- 
tions will  therefore  be  confined  to  certain  striking  features 
of  the  vesicant  action  of  this  substance. 


Variation  in  Susceptibility  of  the  Skin 

Every  worker  who  has  worked  with  mustard  gas  has 
noticed  that  some  individuals  are  much  more  susceptible  to 
skin  burns  from  this  substance  than  are  others.  Marshall  made 
a  study  of  1282  men  at  Edgewood  Arsenal,  using  a  1  per 
cent  and  a  0.01  per  cent  solution  of  mustard  gas  in  paraffin 
oil.  A  small  drop  of  these  solutions  was  applied  to  the  skin 
of  the  forearm  of  the  subject  and  the  arm  allowed  to  remain 
uncovered  for  about  10  minutes.  The  presence  or  absence  of 
a  positive  reaction  is  indicated  by  the  appearance  or  absence 
of  erythema  24  hours  later.     The  results  were  as  follows: 

1%                            0.01%  %  of  Total 

Positive Positive 3.3 

Positive Negative 55 . 3 

Negative Negative 41.4 


172 


CHEMICAL  WARFARE 


The  test  made  on  84  negroes  gave  the  following  results: 


1%  0.01% 

Positive Positive.  .  . 

Positive Negative .  . 

Negative Negative .  . 

Questionable Negative.  . 


%  of  Total 

0.0 

15.0 

78.0 

7.0 


"It  is  seen  from  the  above  tables  that  negroes  as  a  race,  have  a 
much  more  resistant  skin  than  white  men.  No  negro  of  the  84 
examined  reacted  to  the  0.1  per  cent  solution,  and  of  course  none 
would  react  to  a  more  dilute  one.     About  10  per  cent  of  white  men 


s 

a 

o 


0.1 


Concentration  of  Mustard  Gas  Required 

to  Irritate  the  Skin- Subject,  A 

Sensitive  Individual 

X  =Burn  (Brythema):  °  =  Doubtful  :  o  =  No  Burn: 

*JI 

<x 

'< 

k 

. 

_ 

24  32  40 

Time  -Minutes 


64 


FiC.  37. 

react  to  the  0.1  per  cent  solution,  while  2  to  3  per  cent  react  to  the 
0.01  per  cent  solution  or  are  hypersensitive.  About  78  per  cent  of 
the  negroes  fail  to  react  to  the  1  per  cent  solution,  while  only  20  to 
40  per  cent  of  the  white  race  do  not  show  a  reaction." 

The  same  individual  may  also  show  variations  in  suscep- 
tibility and  this  has  also  been  studied  by  Marshall. 

"The  effect  of  exercise  and  sweating  was  investigated.  A  number 
of  individuals  were  given  vapor  burns  (one  to  five  minutes  exposure) 
and  then  exercised  until  in  a  profuse  sweat,  and  then  the  same  exposure 
to  vapors  made.  In  all  cases  the  bum  produced  after  exercising 
was  more  severe.     Sweating  produced  by  having  the  subjects  place 


MUSTARD  GAS' 


173 


tlieir  feet  in  hot  water,  produced  the  same  increase  in  susceptibility. 
That  the  moisture  on  the  skin  produced  by  sweating  is  at  least  partly, 
if  not  entirely,  responsible  for  the  increased  susceptibility,  was  shown 
in  the  following  way:  An  area  of  the  foreami  was  kept  moist  for  a 
few  minutes  with  wet  cotton.  The  sponge  was  then  removed  and 
two  vapor  tests  made,  one  over  the  moist  area  and  one  over  normal, 
dry  skin.  In  all  cases  the  moist  burn  was  the  more  severe,  in  one, 
producing  a  blister  where  the  control  did  not. 

"The  skin  of  different  areas  of  the  body  is  undoubtedly  somewhat 
different  in  its  susceptibility.  All  our  tests'  have  been  applied  to  the 
forearm.  The  hands  are  considerably  more  resistant  than  the  forearm. 
Tests  made  by  the  oil  method  on  the  forearm,  chest,  and  back,  however, 
indicate  very  little  difference  in  susceptibility  of  these  areas.  The 
skin  in  the  neighborliood  of  old  burns  has  been  shown  to  be  more 
susceptible. 

"In  general,  the  same  individual  does  not  become  more  susceptible 
to  skin  burns  from  continued  exposure  to  the  vapor.  The  great  number 
of  tests  which  have  been  made  on  the  same  individual  at  different 
times  and  under  the  same  conditions,  indicate  a  remarkable  constancy 
in  reaction.  A  series  of  men  who  were  tested  at  various  times  during 
a  period  of  four  months,  revealed  slight  changes  from  time  to  time 
in  some  of  the  men.  No  man  who  originally  reacted  to  only  the 
1  per  cent  solution  ever  reacted  to  the  0.01,  and  likewise,  no  man  who 
originally  reacted  to  the  0.01  ever  failed  to  react  to  the  0.1  per  cent. 

"Susceptibility  of  skin  of  animals.  The  paraffin  oil  test  was  used 
on  a  number  of  animals  and  indicated  that  differences  in  susceptibility 
exist  in  different  species  and  in  different  individuals  of  the  same 
species." 


Species 


Number 
Tested 


Percentage  Positive  to 


1  Per 

Cent 


0.1  Per 
Cent 


0.01  Per 
Cent 


Horse 

Dog 

Goat 

Rat 

Mouse 

Rabbit...  . 
Guinea-pig 
Monkey. . . 


1 
91 
11 
10 

7 

2 
12 

9 


100 
83 
55 
30 
70 

100 
33 
22 


100 

35 

36 

20 

14 

0 

0 

0 


100 
0 
0 
0 
0 
0 
0 
0 


174  CHEMICAL  WARFARE 

The  horse  appears  to  be  the  most  sensitive  and  the  monkey 
and  guinea-pig  the  most  resistant  species,  while  the  dog  would 
seem  to  have  a  sensitivity  as  near  man  as  any  of  the  species 
studied.  No  animal  has  yet  been  found  which  will  give  a 
blister  from  the  application  of  mustard  gas. 

Smith,  Clowes  and  Marshall^  have  studied  the  mechanism 
of  absorption  by  the  skin.  They  find  that  it  is  quite  evident 
that  the  mustard  gas  is  at  first  rapidly  taken  up  by  some 
element  on,  or  adjacent  to,  the  surface  of  the  skin  and  for  two 
to  three  minutes  it  may  be  completely  removed,  and  for  ten 
to  fifteen  minutes  partially  removed  by  prolonged  washing 
with  an  organic  solvent,  and  to  a  lesser  extent  with  soap  and 
water. 

An  interesting  phenomenon  is  observed  when  the  untreated 
normal  skin  of  one  subject  is  impressed  for  five  minutes  upon 
an  area  of  skin  of  another  subject,  which  has  been  exposed 
previously  to  the  vapors  of  mustard  gas.  Under  these  circum- 
stances both  donor  and  recipient  may  develop  burns  (due  to 
the  transposition  of  the  poison  from  one  skin  to  another),  the 
intensity  of  which  will  vary  according  to  the  circumstances 
and  the  respective  sensitiveness  of  the  participants.  The  degree 
of  transposition  is  most  strikingly  observed  in  the  intensity 
of  the  burn  on  the  donor's  arm.  If  two  similar  exposures 
are  made  on  the  arm  of  a  sensitive  man,  and  one  of  these 
burns  is  treated,  so  to  speak,  by  contact  for  five  minutes,  with 
the  skin  of  a  resistant  man,  the  treated  burn  will  be  markedly 
less  severe  than  the  control,  in  some  cases  being  entirely  pre- 
vented. If,  however,  the  recipient  is  equally  sensitive  to  or 
more  sensitive  than  the  donor,  the  burns  on  the  latter  will 
exhibit  far  less  difference.  Both  treatments  may  be  effected 
at  once,  using  two  recipients,  one  more,  and  the  other  less, 
resistant  than  the  donor.  In  such  a  case  the  burn  brought 
into  contact  with  the  more  resistant  skin  will  be  the  less  severe. 

Similarly,  if  a  sensitive  individual  impresses  his  arm  alter- 
nately against  burns  of  the  same  concentration  and  exposure 
on  a  resistant  and  sensitive  man,  the  recipient  receives  a  more 
severe  burn  from  the  sensitive  than  from  the  resistant  man. 

This   indicates   that   the    skin    of    a    resistant'  individual 

V.  Pharmacol.,  13,  1  (1919). 


I 


''MUSTARD  GAS"  175 

exhibits  a  greater  affinity  or  capacity  for  mustard  gas  than 
that  of  a  sensitive  one.  There  is  an  actual  partition  of  the 
gas  between  the  two  skins,  with  an  evident  tendency  to  estab- 
lish an  equilibrium  in  which  the  larger  portion  of  the  gas  will 
remain  in  that  skin  which  possesses  the  greater  capacity  for  it. 

"A  tentative  explanation  of  this  phenomenon  can  be  made  as  follows. 
A  three  phase  system  is  involved — the  air  over  the  skin  surface  con- 
stitutes the  outer  phase;  some  fatty  or  keratinous  elements  of  the 
skin,  the  central  phase;  and  a  cellular  portion  of  the  skin  the  inner 
phase.  The  central  phase  is  rich  in  lipoids  and  poor  in  water,  while 
the  inner  phase  is  rich  in  water  and  poor  in  lipoids.  After  exposure 
to  the  vapors  of  dichlorethysulphide  the  central  phase  is  the  absorbing 
agent  and  tends  to  establish  equilibrium  with  the  other  two  phases.  On 
account  of  the  lipoid  nature  of  the  central  phase  no  damage  is  produced 
here  because  the  compound  is  not  hydrolyzed.  On  its  passage  from 
the  central  to  the  inner  phase  hydrolysis  takes  place  within  the  cell 
and  damage  results  when  a  sufficient  concentration  of  hydrochloric  acid 
is  attained.  The  outer  phase  is  constantly  being  freed  from  vapor  by 
diffusion  and  convection  currents,  so  more  and  more  can  evaporate 
from  the  central  phase.  The  susceptibility  of  an  individual  depends 
on  the  relative  power  of  the  central  phase  to  hold  the  poison  in  an 
inactive  form  (not  hydrolyzed)  and  prevent  its  entry  into  the  inner 
phase  at  a  sufficient  velocity  to  result  in  the  formation  of  a  toxic 
concentration.  We  do  not  attempt  to  localize  the  central  or  inner 
phases  with  any  definite  structure  of  the  skin.  As  mustard  is  known 
to  penetrate  the  sebaceous  ducts  the  fat  here  might  form  one  phase 
and  the  epithehal  lining  another." 


^ 


Tactical  Use  of  Mustard  Gas 


As  before  stated,  mustard  gas,  like  most  other  materials  used 
in  war,  was  discovered  in  peace.  Indeed,  Victor  Meyer  in  1886 
worked  out  fairly  completely  its  dangerous  characteristics.  Like 
phosgene  and  chlorine  used  before  it,  the  materials  for  its  pro- 
duction were  available  in  considerable  quantities  through  the 
manufacture  of  components  either  for  dyes  or  photographic 
chemicals. 

Mustard  gas,  besides  being  highly  poisonous,  has  so  many 
other  important  qualities  as  to  have  given  it  the  designation 
during  the  war  of  the  ''king  of  gases."    That  broad  distinction 


176  CHEMICAL  WARFARE 

it  still  holds.  Its  introduction  at  Ypres,  on  the  night  of  July  12, 
1917,  changed  completely  the  whole  aspect  of  gas  warfare  and  to 
a  considerable  extent  the  whole  aspect  of  warfare  of  every  kind. 
fit  is  highly  poisonous,  being  in  that  respect  one  of  the  most 
useful  of  all  war  gases.  It  produces  no  immediate  discomfort. 
It  has  a  considerable  delay  action.  It  burns  the  body  inside  or 
out,  wherever  there  is  moisture.  Eyes,  lungs  and  soft  parts  of 
the  body  are  readily  attacked.  It  lingers  for  two  or  three  days 
in  the  warmest  weather,  while  in  cold,  damp  weather  it  is  dan- 
gerous for  a  week  or  ten  days,  and  in  still  colder  weather  may 
be  dangerous  for  a  month  or  longer  whenever  the  weather 
jwarms  up  sufficient  to  volatilize  the  liquid.  It  is  only  slowly 
destroyed  in  the  earth,  making  digging  around  shell  holes 
dangerous  for  weeks  and  months  and  in  some  cases  possibly  a 
year  or  more. 

The  Germans  first  used  it  simply  to  get  casualties  and  inter- 
fere with  or  break  up  the  threatened  heavy  attacks  by  the  British 
on  the  Ypres  salient.  While  not  stopping  the  inauguration  of 
these  attacks  in  the  fall  of  1917,  the  German  use  of  mustard  gas 
was  so  effective  as  to  delay  the  beginning  of  those  attacks  for  at 
least  two  weeks  and  thus  gain  valuable  time  for  the  Germans, 
besides  causing  serious  casualties  with  consequent  partial  break- 
up of  companies,  regiments  and  divisions  in  the  English  Army. 

The  German  used  his  mustard  gas  throughout  the  fall  of 
1917  and  the  winter  of  1917  and  1918,  as  above  stated,  to  pro- 
duce casualties,  to  destroy  morale,  to  break  up  units,  and  to 
interfere  with  operations  generally.  During  that  time,  however, 
he  developed  a  more  scientific  use  and  when  he  started  his  big 
offensives  in  March,  April,  May  and  June,  1918,  he  used  mustard 
gas  before  the  battles  to  cause  losses,  break  up  units  and  destroy 
morale,  and  also  during  the  progress  of  battles  to  completely 
neutralize  strong  points  which  he  felt  he  did  not  want  to  attempt 
to  take  by  direct  assault.  Perhaps  the  most  noted  case  of  this 
was  at  Armentieres  in  April,  when  he  deluged  the  city  to  such 
an  extent  that  mustard  gas  is  said  to  have  actually  run  in  the 
streets.  So  effective  was  this  gassing  that  not  only  did  the 
British  have  to  withdraw  from  the  city  but  the  Germans  could 
not  enter  it  for  more  than  two  weeks.  It,  however,  enabled  the 
Germans  to  take  the  city  with  practically  no  loss  of  life.    There 


"9: 


'^ MUSTARD  GAS"  177 

ere  numerous  other  cases  on  a  smaller  scale  where  mustard  gas 
as  used  in  the  same  way. 

On  account  of  its  persistence  it  has  been  generally  referred 
to  as  a  defensive  gas  and  for  that  purpose  it  is  incomparable. 
The  use  of  sufficient  quantities  of  mustard  gas  will  almost  cer- 
tainly stop  the  occupation  of  areas  by  the  enemy  and  probably 
even  stop  his  crossing  them.  It  also  enables  strong  points  which 
it  is  not  desired  to  attack  to  be  completely  neutralized, — that  is, 
made  so  unhabitable  that  the  area  must  be  evacuated. 

A  use  that  was  proposed  toward  the  end  of  the  war,  and  that 
will  undoubtedly  be  made  of  the  gas  in  the  future,  is  to  have  it 
planted  in  drums  in  the  ground  and  exploded  when  an  enemy 
is  attempting  to  advance.  This  would  be  a  highly  economic  way 
to  distribute  great  quantities  of  the  material  at  the  moment  and 
in  the  place  most  needed.  It  has  even  been  proposed,  and  this 
would  seem  entirely  feasible,  to  sprinkle  certain  of  these  areas 
with  mustard  gas  by  means  of  sprinklers  attached  to  drums  or 
even  tanks  mounted  on  trucks. 

Just  before  the  Armistice  the  German  made  another  develop- 
ment in  the  use  of  mustard  gas.  Instead  of  the  ordinary  amount 
of  explosive,  which  only  fairly  opened  up  the  shell  and  allowed 
the  liquid  to  escape,  he  filled  nearly  30  per  cent  of  the  total  space 
of  the  shell  with  high  explosive.  This  completely  broke  up  the 
shell  and  distributed  the  greater  part  of  the  liquid  mustard  gas 
in  the  form  of  a  fine  spray.  This  spray,  when  breathed,  proved 
extremely  deadly,  as  might  be  expected  from  the  fact  that  when 
in  the  form  of  minute  particles  one  can  draw  into  the  lungs  in  a 
single  breath  one  hundred  times  or  more  the  amount  that  he 
would  get  of  pure  gas. 

Since  mustard  gas  has  such  a  delay  action  and  is  effective 
in  such  small  concentrations  it  can  be  used  very  effectively  in 
small  calibre  guns,  as  the  75  mm.  or  3-inch.  Furthermore,  since 
it  lasts  for  two  or  three  days  at  the  very  least,  a  small  number 
of  guns  can  keep  a  very  large  area  neutralized  with  the  gas. 
With  phosgene  and  similar  non-persistent  gases  that  volatilize 
almost  completely  upon  the  burst  of  the  shell  it  is  necessary  to 
build  up  a  high  concentration  immediately.  The  exact  opposite 
is  true  of  mustard  gas.  Mustard  gas  can  be  fired  very  slowly 
with    the    certain    knowledge    that    all    shells    fired    at    one 


178  CHEMICAL  WARFARE 

moment  will  be  effective  when  the  next  is  fired,  though  twelve 
hours  or  more  may  intervene  between  the  first  and  last  firing. 
Thus,  while  with  phosgene  a  large  number  of  guns  are  needed 
for  a  gas  attack,  with  mustard  gas  the  number  can  be  reduced  to 
one-tenth  or  even  less.  Mustard  gas  may  be  in  the  future  and 
has  been  in  the  past  used  safely  in  hand  grenades  because  of  its 
very  low  vapor  tension,  whereby  the  pressure  at  ordinary  tem- 
peratures is  exceedingly  low.  This  has  an  important  bearing  on 
cylinders  and  other  containers  for  shipping  mustard  gas,  that  is, 
they  need  be  only  strong  enought  to  be  safe  against  handling 
and  not  to  withstand  the  high  pressure  encountered  with  phos- 
gene or  chlorine  cylinders. 

In  the  future,  mustard  gas  will  be  used  in  all  the  ways  above 
stated  and  undoubtedly  in  many  more.  It  can  be  fired  in  large 
quantities  upon  strong  points  to  force  their  evacuation.  It  can 
be  fired  on  the  flank  of  attacking  armies  for  protection  against 
counter-attacks.  It  can  be  fired  against  the  enemy  artillery  at 
all  times  to  silence  them  and  stop  their  firing.  It  was  thus  used 
by  the  Americans  in  the  Argonne  against  the  enemy  on  the  east 
bank  of  the  Meuse  River,  this  river  separating  the  American  and 
German  armies.  It  was  extremely  effective  in  stopping  the 
enemy's  artillery.  The  high  explosive  mustard  gas  shell,  not 
only  because  of  its  persistency  but  because  of  its  quick  deadliness, 
can  be  fired  singly  and  be  depended  upon  to  do  its  work  wher- 
ever there  be  men  or  animals.  One  of  the  greatest  uses  will  be 
by  simple  sprinkling  from  aeroplanes. 

The  future  will  see  mustard  gas  used  at  nearly  all  times  with 
a  certain  quantity  of  a  powerful  lachrymator  or  tear  gas.  This 
is  for  the  reasons,  as  stated  in  the  beginning,  that  mustard  gas 
causes  no  immediate  discomfort  and  has  no  objectionable  smell. 
Accordingly,  if  the  battle  be  critical,  men  may  continue  to  fight 
from  four  to  eight  hours  in  a  mustard  gas  atmosphere  without 
masks.  It  is  true  the  casualties  will  be  high  with  a  high  death 
rate.  Nevertheless,  this  period  of  time  might  enable  the  artil- 
lery to  do  such  effective  work  as  to  completely  stop  an  attack. 
If,  however,  at  the  instant  mustard  gas  firing  is  begun  a  number 
of  powerful  lachrymatory  shells  are  sent  over,  the  immediate 
wearing  of  the  mask  is  forced.     The  enemy  is  then  subject  to 


''MUSTARD  GAS"  179 

all  the  burning  effects  of  mustard  gas  as  well  as  the  discomfort 
of  long  wearing  of  the  mask. 

It  may  confidently  be  expected  that  that  further  develop- 
ments in  the  use  of  mustard  gas  will  be  made,  as  well  as  further 
developments  in  methods  of  throwing  it  upon  the  enemy  or  of 
bursting  shell  containing  it  in  his  midst. 


X 


CHAPTER  X 
ARSENIC    DERIVATIVES 


Since  arsenic  is  well  known  as  an  insecticide  in  the  form  of 
lead  arsenate,  arsenic  acid  etc.,  and  in  pharmacy,  specially  in 
the  form  of  salvarsan  and  neosalvarsan,  it  is  not  surprising  that 
the  Germans  should  have  endeavored  to  discover  an  arsenic 
derivative  which  would  be  of  value  from  the  point  of  view  of 
chemical  warfare.  Very  early  in  the  war  persistent  rumors 
were  circulated  that  the  Germans  were  to  use  arsine.  These 
rumors  led  to  the  use  of  sodium  permanganate  in  the  canister, 
but  as  far  as  is  known,  no  arsine  was  actually  used.  Another 
suggestion  which  received  considerable  attention  from  American 
workers  was  the  use  of  arsenides,  which  might  decompose  under 
the  influence  of  the  atmospheric  moisture  with  the  liberation  of 
arsine.  Calculation  of  the  amount  of  arsenide  necessary  to  estab- 
lish a  lethal  concentration  of  arsine  showed,  however,  that  there 
was  no  possibility  of  using  the  material  on  the  field. 

Because  of  the  use  of  arsenic  trichloride  in  the  manufacture 
of  organic  arsenic  compounds,  a  method  of  preparation  was 
developed  from  arsenic  trioxide  and  sulfur  chloride  or  hydrogen 
chloride.  It  was  also  shown  experimentally  that  the  phosgene 
of  the  tail  gas  of  phosgene  plants  might  be  converted  into  arsenic 
trichloride  by  reaction  with  arsenic  trioxide.  Charcoal  is  the 
catalyzer  of  this  reaction. 

Arsenic  trichloride  is  also  of  interest  because  it  was  one  of 
the  constitutents  of  the  mixture  vincennite,  early  used  by  the 
French.  This  was  a  mixture  of  hydrocyanic  acid,  stannic  chlor- 
ide, arsenic  trichloride  and  chloroform.  While  extensively  used 
at  first,  it  was  gradually  replaced  by  phosgene. 

Arsenic  triflouride  was  also  prepared  by  the  action  of  sulfuric 
acid  upon  a  mixture  of  calcium  flouride  and  arsenic  trioxide. 

180 


ARSENIC   DERIVATIVES 


181 


The  compound  is  very  easily  decomposed  b}^  the  moisture  of  the 
air,  and  furthermore  is  not  very  toxic. 

Organic  arsenic  derivatives  are  the  most  important  compounds 
from  the  military  point  of  view.  The  first  substance  used  was 
diphylchloroarsine,  a  white  solid,  which  readily  penetrated 
the  canister  and  caused  sneezing.  This  was  used  alone,  and  in 
solution  in  phenyl  dichloroarsine.  Later  methyl  and  ethyl 
dichloroarsines  were  introduced. 


Methyldichloroarsine 

The  Germans  apparently  used  ethyldichloroarsine  because 
they   had   no   suitable   method   for  the   preparation   of   methyl 


Fig.  38. — Apparatus  for  the  Manufacture  of  Methyldichloroarsine. 

dichloroarsine,  which  is  a  more  satisfactory  material.  The 
Chemical  Warfare  Service  developed  the  following  method  of 
preparation  of  the  methyl  derivative.  Sodium  arsenite 
(NaaAsOg)  is  prepared  by  dissolving  arsenic  trioxide  in  sodium 
hydroxide  solution.    The  action  of  methyl  sulfate  at  85°  C.  gives 


182  ,      .  .CHEMICAL   WARFARE 

disodium  methyl  arsenite,  Na^^CHgAsOa.  Sulfur  dioxide  reduces 
the  arsenite  to  methyl  arsine  oxide,  CHgAsO,  wliich  is  then  re- 
acted with  hydrochloric  acid  to  give  methyl  dichloroarsine.  The 
final  product  is  distilled  from  the  mixture  and  condensed.  This 
material  costs  from  two  to  two  and  a  half  dollars  per  pound  for 
chemicals  (war  prices). 

Methyldichloroarsine  is  a  colorless  liquid  of  powerful  burn- 
ing odor,  which  boils  at  132°  C.  It  is  somewhat  soluble  in  water 
and  is  soluble  in  organic  solvents.  The  specific  gravity  is  1.838 
at  20°  C.  The  vapor  pressure  at  25°  was  found  to  be  10.83  mm. 
mercur}^  Not  only  is  the  material  toxic  but  it  has  remarkable 
vesicant  properties,  comparing  favorably  with  mustard  gas  in 
this  respect. 

Ethyldichloroarsine,  which  was  used  by  the  Germans,  was 
prepared  by  the  method  given  above,  using  ethyl  sulfate,  but  the 
yield  was  never  over  20  per  cent.  In  general  this  has  properties 
similar  to  the  methyl  derivative. 

DiPHENYLCHLOROARSINE 

The  best  known  of  the  arsenicals,  however,  is  diphenylchloro- 
arsine  or  sneezing  gas.  Although  this  is  an  old  compound  (hav- 
ing been  prepared  by  German  chemists  in  1885),  there  was  no 
method  for  its  preparation  on  a  large  scale  when  first  introduced 
into  chemical  warfare.  It  was  finally  discovered  that  the  inter- 
action of  triphenyl  arsine  with  arsenic  trichloride  was  fairly 
satisfactory  and  a  plant  was  erected  for  its  manufacture. 

When  pure,  diphenylchloroarsine  is  a  colorless  solid,  melting 
at  44°.  Because  of  this,  it  was  always  used  in  solution  in  a 
toxic  gas  or  in  a  shell  which  contained  a  large  amount  of  ex- 
plosive so  that  on  the  opening  of  the  shell  the  material  would  be 
finely  divided  and  scattered  over  a  wide  territory. 

Its  value  lay  in  the  fact  that  the  fine  particles  readily 
penetrated  the  ordinary  mask  and  caused  the  irritation  of  the 
nose  and  throat,  which  resulted  in  sneezing.  This  necessitated 
the  perfection  of  special  smoke  filters  to  remove  the  particles, 
after  which  the  other  toxic  materials  were  removed  by  the 
absorbent  in  the  canister. 

It  causes  sneezing  and  severe  burning  sensations  in  the  nose, 


ARSENIC  DERIVATIVES  183 

throat  and  lungs  in  concentrations  as  slight  as  1  part  in  10 
million.  In  higher  concentrations,  say  1  in  200  to  500  thousand 
it  causes  severe  vomiting.  While  neither  of  these  effects  are 
dangerous  or  very  lasting,  still  higher  concentrations  are  serious, 
as  in  equal  concentrations  diphenylchloroarsine  is  more  poison- 
ous than  phosgene. 

Various  other  arsenical  chemicals  were  developed  in  the 
laboratory,  but  with  one  or  two  exceptions  they  were  not  as 
valuable  as  diphenylchloroarsine  and  methyldichloroarsine  and 
were  therefore  discarded. 

German  Methods  for  Manufacturing  Arsenicals  ^ 

Diphenylchloroarsine 

^'This  substance  (Blue  Cross)  was  a  famous  gas  of  the  Germans 
and  was  made  in  large  quantities.  The  method  used  b^  the  Germans 
was  different  from  the  one  worked  out  by  the  Allies,  and  on  account 
of  the  fact  that  the  German  method  could  be  carried  out  without 
specially  designed  apparatus  and  required  as  raw  materials  substances 
readily  obtainable,  it  was  probably  preferable.  It  is  doubtful,  however, 
whether  the  Allies  would  have  made  this  gas,  for  as  the  result  of  its 
use  no  fatalities  were  reported.  The  German  process  consisted  in 
preparing  phenylarsenic  acid  by  condensing  benzene  diazonium  chloride 
with  sodium  arsenite.  The  acid  was  next  reduced  by  sulfur  dioxide 
to  phenylarsenous  acid,  which  was,  in  turn,  condensed  with  the 
diazonium  compound  to  form  diphenylarsenic  acid.  This  acid  was 
reduced  to  diphenylarsenous  oxide,  which  with  hydrochloric  acid  yielded 
diphenychloroarsine.  The  chemical  equations  for  the  reactions  will 
make  clearer  the  st6ps  involved. 

CcHfiNaCl  -f  Na,As03  =  CeHsAsOaNaa  +NaCl  +N2 
CcHsAsOsNaz  +2HC1  =C6H5As03Ho  +2NaCl 
CeHAsOsHj  +SO2  +H2O  =  C6HASO2H0  +H2SO4 

ICeHsNjCl  +C6H5As02Na2  =  (C6H6)2As02Na  +NaCl  -f-N^ 
(C6H6)2As02Na  +HCI  =  (C«H5)2As02H  +NaCl 
2(C6H5)2As02H  4-2SO2  +H2O  =  [(CeHOzAsbO  -f  2H2SO. 
[(C6H6)2Asl20  +2HC1  =2(C6H5)2AsCl  +H2O. 
"The  entire  process  was  carried  out  at  Hochst.    The  method  used  at 
Hochst  was  as  follows :  In  preparing  the  diazonium  solution,  3  kg.  mols 
^■pf  aniline  were  dissolved  in  3000  liters  of  water  and  the  theoretical 
^B     »Norris,  J.  Ind.  Eng.  Chem.,  11,  825  (1919). 


184  CHEMICAL  WARFARE 

quantity  of  hydrochloric  acid.  The  temperature  of  the  solution  was 
reduced  to  between  0°  and  5°  and  the  theoretical  amount  of  sodium 
nitrite  added.  The  -reaction  was  carried  out  in  a  wooden  tank  of 
the  usual  form  for  the  preparation  of  diazomum  compounds.  A  solu- 
tion of  sodium  arsenite  was  prepared  which  contained  20  per  cent 
excess  of  oxide  over  that  required  to  react  with  the  aniline  used.  The 
arsenous  oxide  was  dissolved  in  sodium  carbonate,  care  being  taken 
to  have  enough  of  the  alkali  present  to  neutralize  all  of  the  acid 
present  in  the  solution  of  the  diazonium  salt.  To  the  solution  of  the 
sodium  arsenite  were  added  20  kg.  of  copper  sulfate  dissolved  in  water, 
this  being  the  amount  required  when  3  kg.-mols  of  aniline  are  used. 
The  solution  of  the  diazonium  compound  was  allowed  to  flow  slowly 
into  the  solution  of  the  arsenite  while  the  temperature  was  maintained 
at  15°.  The  mixture  was  constantly  stirred  during  the  addition  which 
requires  about  3  hrs.  After  the  reaction  was  complete,  the  matej'ial 
was  passed  through  a  filter  press  in  order  to  remove  the  coupling  agent 
and  the  tar  which  had  been  formed.  Hydrochloric  acid  was  next  added 
to  the  clear  solution  to  precipitate  phenylarsenic  acid,  the  last  portions 
of  which  were  removed  by  the  addition  of  salt. 

"The  phenylarsenic  acid  was  next  reduced  to  phenylarsenous  acid 
by  means  of  a  solution  of  sodium  bisulfite,  about  20  per  cent  excess 
of  the  latter  over  the  theoretical  amount  being  used.  For  100  parts 
of  arsenic  acid,  400  parts  of  solution  were  used.  The  reaction  was 
carried  out  in  a  wooden  vessel  and  the  mixture  stirred  during  the 
entire  operation.  A  temperature  of  80°  was  maintained  by  means 
of  a  steam  coil.  Phenylarsenous  acid  separated  as  an  oil.  The  aqueous 
solution  was  decanted  from  the  oil,  which  was  dissolved  in  a  solution 
of  sodium  hydroxide,  40°  Be.  The  solution  of  the  sodium  salt  of 
phenylarsenous  acid  was  treated  with  water  so  that  the  resulting 
solution  had  a  volume  of  6  cu.  m.  when  3  kg.-mols  of  the  salt  were 
present.  Ice  was  next  added  to  reduce  the  temperature  to  15°  and 
a  solution  of  benzene  diazonium  chloride,  prepared  in  the  manner 
described  for  the  first  operation,  was  slowly  added.  After  the  coupling, 
diphenylarsenic  acid  was  precipitated  by  means  of  hydrochloric  acid. 
The  acid  was  removed  by  means  of  a  filter  press  and  dissolved  in 
hydrochloric  acid,  20°  Be.  For  one  part  of  diphenylarsenic  acid, 
3  parts  of  hydrochloric  acid  were  used.  Into  this  solution  was  passed 
5  per  cent  excess  of  sulfur  dioxide  over  that  required  for  the  reduction. 
The  sulfur  dioxide  used  was  obtained  from  cylinders  which  contained 
it  in  liquid  condition. 

"The  reduction  was  carried  out  in  an  iron  tank  lined  with  tiles 
and  a  temperature  of  80°  was  maintained.    About  8  hrs.  were  required 


ARSENIC  DERIVATIVES  185 

for  the  reaction.  The  diphenylarsenic  acid  on  reduction  by  the  sulfur 
dioxide  was  converted  into  diphenylarsenous  oxide  which,  in  the  presence 
of  the  hydrochloric  acid,  was  converted  into  diphenylchloroarsine, 
which  separated  as  an  oil.  The  oil  was  next  removed  and  heated  in 
the  best  vacuum  obtainable  until  it  was  dry  and  free  from  hydrochloric 
acid.  The  compound  melted  at  34°.  It  was  placed  in  iron  tanks  for 
shipment.  The  yield  of  diphenylchloroarsine  calculated  from  the  aniline 
used  was  from  25  to  30  per  cent  of  the  theoretical.  No  marked  trouble 
was  observed  in  handling  the  materials  and  no  serious  poisoning  cases 
were  reported. 

DiPHENYLCYANOARSINE 

"This  compound  was  prepared  by  treating  diphenylchloroarsine 
with  a  saturated  aqueous  solution  of  potassium  or  sodium  cyanide. 

(C6H5)2AsCl  +NaCN  =  (C6H6)2AsCN  +NaCl. 

Five  per  cent  excess  of  the  alkaline  cyanide  was  used.  The  reaction 
was  carried  out  at  60°  with  vigorous  stirring.  The  yield  was  nearly 
theoretical. 

Ethyldichloroarsine 

"This  compound  was  prepared  at  Hochst  from  ethylarsenous  oxide 
which  was  obtained  from  the  Badische  Anilin  und  Soda  Fabrik. 

"Preparation  of  Ethylarsenous  Oxide — The  compound  was  pre- 
pared by  treating  sodium  arsenite  with  ethyl  chloride  under  pressure. 
The  resulting  sodium  salt  of  ethylarsenic  acid  was  converted  into  the 
free  acid  and  reduced  by  sulfur  dioxide.  The  ethylarsenous  acid  formed 
in  this  way  lost  water  and  was  thereby  transformed  into  ethylarsenous 
oxide.     The  reactions  involved  are  as  follows: 

C2H5CI  +Na3As03  =  CiHsAsOsNaa  +NaCl 

CzH^AsOsNaa  +2HC1  =  C2H5ASO3H2  +2NaCl 

C2H5ASO3H2  +SO2  +H2O  =  C2H5ASO2H2  +H2SO4 

2C2H5ASO2H2  =  (C2H5AS)20  +H2O. 

"The  ethyl  chloride  used  in  the  preparation  was  in  part  made  in 
this  factory,  and  in  part  received  from  other  sources.  As  ethyl  chloride 
is  an  important  product  used  in  peace  time,  it  is  not,  therefore, 
essentially  a  war  product  and  its  preparation  was  not  described. 

"In  preparing  the  solution  of  sodium  arsenite,  one  molecular  weight 
of  arsenous  oxide  was  dissolved  in  a  solution  containing  8  molecular 


186  CHEMICAL  WARFARE 

weights  of  sodium  hydroxide.  The  solution  of  the  base  was  prepared 
from  a  50  per  cent  solution  of  sodium  hydroxide  to  which  enough  solid 
alkali  was  added  to  make  the  solution  a  55  per  cent  one.  In  one 
operation  660  kg.  of  arsenous  oxide  were  used.  For  100  parts  of 
arsenous  oxide,  130  parts  of  ethyl  chloride  were  used,  this  being  the 
theoretical  amount  of  the  latter. 

"The  reaction  was  carried  out  in  a  steel  autoclave  of  about  300  liters 
capacity.  The  temperature  was  maintained  at  between  90°  and  95°. 
The  ethyl  chloride  was  pumped  in,  in  3  or  4  portions,  and  the  pressure 
in  the  autoclave  was  kept  at  from  10  to  15  atmospheres.  The  several 
portions  of  ethyl  chloride  were  introduced  at  intervals  of  about  IV2 
hrs.  During  the  entire  reaction,  the  contents  of  the  autoclave  were 
vigorously  stirred.  After  all  the  ethyl  chloride  had  been  added,  the  ma- 
terial was  stirred  from  12  to  16  hrs.,  at  the  end  of  which  time  the 
pressure  had  fallen  to  about  6  atmospheres.  The  excess  of  ethyl  chlo- 
ride and  the  alcohol  formed  in  the  reaction  were  next  distilled  off.  At 
this  point  a  sample  of  the  solution  was  drawn  off  for  testing.  This 
was  done  by  determining  the  amount  of  arsenite  present  in  the  solution. 
If  not  more  than  20  per  cent  of  sodium  arsenite  had  not  reacted, 
the  preparation  was  considered  satisfactory.  Water  was  then  added  to 
the  contents  of  the  autoclave  in  sufficient  amount  to  dissolve  the  solid 
material.  The  product  was  next  drawn  over  into  a  tank  and  neutralized 
with  sulfuric  acid.  It  was  then  treated  with  sulfur  dioxide  gas  until 
there  was  an  excess  of  the  latter  present.  The  mixture  was  then  heated 
to  about  70°  when  the  ethylarsenous  oxide  precipitated  as  a  heavy  oil. 
This  was  readily  separated  and  shipped  without  further  purification. 
The  yield  of  ethylarsenous  oxide,  from  arsenic  oxide,  was  from  80  to  82 
per  cent  of  a  product  which  contained  about  93  per  cent  of  pure  ethylar- 
senous oxide. 

"Preparation  of  Ethyldichloroarsine — The  compound  was  pre- 
pared by  treating  ethylarsenous  oxide  with  hydrochloric  acid.  The 
reaction  is  as  follows: 

C.H5ASO +2HC1  =  C2H5ASCI +H2O. 

The  operation  was  carried  out  in  an  iron  kettle  lined  with  lead, 
which  was  cooled  externally  by  means  of  water  and  which  was  furnished 
with  a  lead  covered  stirrer.  To  the  kettle,  which  contained  from  500 
to  1000  kg.  of  hydrochloric  acid  left  over  from  the  previous  operation, 
were  added  4000  kg.  of  ethylarsenous  oxide.  The  gaseous  hydrochloric 
acid  was  next  led  in.  The  kettle  was  kept  under  slightly  diminished 
pressure  in  order  to  assist  in  the  introduction  of  hydrochloric  acid.    The 


ARSENIC  DERIVATIVES  187 

temperature  during  the  reaction  must  not  rise  above  95°.  When  the 
hydrochloric  acid  was  no  longer  absorbed  and  was  contained  in  appre- 
ciable quantities  in  the  issuing  gases,  the  operation  was  stopped.  This 
usually  occurred  at  the  end  of  from  one  to  two  days.  The  product 
of  the  reaction  was  drawn  off  by  means  of  a  water  pump  and  heated 
in  a  vacuum  until  drops  of  oil  passed  over.  The  residue  was  passed 
over  to  a  measuring  tank  and  finally  to  tank-wagons  made  of  iron. 
The  yield  of  the  product  was  practically  the  theoretical. 

On  account  of  the  volatility  of  the  compound  and  its  poisonous 
character,  the  apparatus  in  which  it  was  prepared  was  surrounded 
by  an  octagonal  box,  the  sides  of  which  were  fitted  with  glass  windows. 
Through  this  chamber  a  constant  supply  of  air  was  drawn.  This  was 
led  into  a  chimney  where  the  poisonous  vapors  were  burned.  The  gases 
given  off  during  the  distillation  of  the  product  were  passed  through 
a  water  scrubber.". 

J   *' Lewisite" 

The  one  arsenical  which  created  the  most  discussion  during 
the  War,  and  about  which  many  wild  stories  were  circulated, 
was  ''Lewisite,"  or  as  the  press  called  it,  ** Methyl."  Its  dis- 
covery  and  perfection  illustrate  the  possibilities  of^esearch 
as  applied  to  Chemical  Warfare,  and  points  to  the  need  of  a 
permanent  organization  to  carry  on  such  work  when  the  pres- 
sure of  the  situation  does  not  demand  such  immediate  results. 

The  reaction  of  ethylene  and  sulfur  chloride,  which  led  to 
the  preparation  of  mustard  gas,  naturally  led  the  organic 
chemists  to  investigate  the  reaction  of  this  gas  and  other  unsat- 
urated hydrocarbons,  such  as  acetylene,  upon  other  inorganic 
chlorides,  such  as  arsenic,  antimony  and  tin.  There  was  little 
absorption  of  the  gas,  either  at  atmospheric  or  higher  pressures, 
and  upon  distilling  the  reaction  product,  most  of  the  gas  was 
evolved,  showing  that  no  chemical  reaction  had  taken  place. 
However,  when  a  catalyser,  in  the  form  of  aluminium  chloride, 
was  added,  Capt.  Lewis  found  that  there  was  a  vigorous  re- 
action and  that  a  highly  vesicant  product  was  formed.  The 
possibilities  of  this  compound  were  immediately  recognized  and 
the  greatest  secrecy  was  maintained  regarding  all  the  details 
of  preparation  and  of  the  properties  of  this  new  product.  At 
the  close  of  the  War,  this  was  considered  one  of  the  most  valu- 


188  CHEMICAL  WARFARE 

able  of  Chemical  Warfare  secrets,  and  therefore  publication 
of  the  reactions  involved  were  withheld.  Unfortunately  or 
otherwise,  the  British  later  decided  to  release  the  material  for 
publication,  and  details  may  be  found  in  an  article  by  Green 
and  Price  in  the  Journal  of  the  Chemical  Society  for  April,  1921. 
It  must  be  emphasized  that  the  credit  for  this  work  belongs, 
not  to  these  authors,  but  to  Capt.  "W.  Lee  Lewis  and  the  men 
who  worked  with  him  at  the  Catholic  University  branch  of  the 
American  University  Division  (the  Research  Division  of  the 
C.  W.  S.). 

On  a  laboratory  scale,  acetylene  is  bubbled  through  a  mix- 
ture of  440  grams  of  anhydrous  arsenic  trichloride  and  300 
grams  of  anhydrous  aluminium  chloride.  Absorption  is  rapid 
and  much  heat  is  developed.  After  six  hours,  about  100  grams 
of  acetylene  is  absorbed.  The  reaction  product  was  dark 
colored  and  viscid,  and  had  developed  a  very  powerful  odor, 
suggestive  of  pelargoniums.  Attempts  to  distill  this  product 
always  led  to  violent  explosions.  (It  may  be  stated  here  that 
Lewis  was  able  to  perfect  a  method  of  distillation  and  separa- 
tion of  the  products  formed,  so  that  pure  materials  could  be 
obtained,  with  little  or  no  danger  of  explosion,)  The  English 
chemists  therefore  decomposed  the  product  with  ice-cold  hydro- 
chloric acid  solution  of  constant  boiling  point  (this  suggestion 
was  the  result  of  work  done  by  Lewis).  The  resulting  oil  was 
then  distilled  in  a  current  of  vapor  obtained  from  constant 
boiling  hydrochloric  acid  and  finally  fractionated  into  three 
parts. 

The  first  product  obtained  consist  in  the  addition  of  one 
acetylene  to  the  arsenic  trichloride  molecule,  and,  chemically,  is 
ehlorovinyldichloroarsine,  CHCl  :  CH  •  AsCla,  a  colorless  or 
faintly  yellow  liquid,  boiling  at  93°  at  a  pressure  of  26  mm. 
A  small  quantity,  even  in  very  dilute  solution,  applied  to  the 
skin  causes  painful  blistering,  its  virulence  in  this  respect 
approaching  that  of  mustard  gas.  It  is  more  valuable  than 
mustard  gas,  however,  in  that  it  is  absorbed  through  the  skin, 
and  as  stated  on  page  23,  three  drops,  placed  on  the  abdomen 
of  a  rat,  will  cause  death  in  from  one  to  three  hours.  It  is 
also  a  very  powerful  respiratory  irritant,  the  mucous  mem- 
brane of  the  nose  being  attacked  and  violent  sneezing  induced. 


ARSENIC  DERIVATIVES  189 

More  prolonged  exposure  leads  to  severe  pain  in  the  throat 
and  chest. 

The  second  fraction  {/3,  ^'-dichlorodivinylchloroarsine)  is  a 
product  resulting  from  the  addition  of  two  acetylene  molecules 
to  one  arsenic  trichloride,  and  boils  at  130°  to  133°  at  26  mm. 
It  is  much  less  powerful  as  a  vesicant  than  chlorovinyldichlo- 
roarsine,  but  its  irritant  properties  on  the  respiratory  .system 
are  much  more  intense. 

The  third  fraction,  p,  p',  /8"-trichlorotrivinylarsine, 
(CHCl  :CH)3As,  is  a  colorless  liquid,  boiling  at  151°  to  155° 
at  28  mm.,  which  solidifies  at  3°  to  4°.  It  is  neither  a  strong 
vesicating  agent  nor  a  powerful  respiratory  irritant.  At  the 
same  time,  its  odor  is  pungent  and  most  unpleasant  and  it 
induces  violent  sneezing. 


r 


CHAPTER  XI 
/   CARBON  MONOXIDE 

Carbon  monoxide,  because  of  its  cheapness,  accessibility  and 
ease  of  manufacture,  has  been  frequently  considered  as  a  possible 
war  gas.  Actually,  it  appears  never  to  have  been  used  intention- 
ally for  such  purposes.  There  are  several  reasons  for  this.  First, 
its  temperature  of  liquefaction  at  atmospheric  pressure  is 
—139°  C.  This  means  too  high  a  pressure  in  the  bomb  or  shell 
at  ordinary  temperatures.  Secondly,  the  weight  of  carbon  mon- 
oxide is  only  slightly  less  than  that  of  air,  which  keeps  it  from 
rolling  into  depressions,  dugouts  and  trenches,  as  in  the  case  of 
ordinary  gases,  and  also  permits  of  its  rather  rapid  rise  and  dis- 
sipation into  the  surrounding  atmosphere.  A  third  reason  is  its 
comparatively  low  toxic  value,  which  is  only  about  one-fifth  that 
of  phosgene.  However,  as  it  can  be  breathed  without  any  dis- 
comfort, and  as  it  has  some  delay  action,  its  lack  of  poisonous 
properties  would  not  seriously  militate  against  its  use  were  it 
not  for  the  other  reasons  given. 

It  is,  nevertheless,  a  source  of  serious  danger  both  in  marine 
and  land  warfare.  Defective  ventilation  in  the  boiler  rooms  of 
ships  and  fires  below  decks,  both  in  and  out  of  action,  are 
especially  dangerous  because  of  the  carbon  monoxide  which  is 
produced.  In  one  of  the  naval  engagements  between  the  Ger- 
mans and  the  English,  defective  high  explosive  shell,  after  pene- 
trating into  enclosed  portions  of  the  ship,  evolved  large  quan- 
tities of  carbon  monoxide  and  thus  killed  some  hundreds  of  men. 
On  shore,  machine  gun  fire  in  enclosed  spaces,  such  as  pill  boxes, 
and  in  tanks,  liberates  relatively  large  quantities  of  carbon  mon- 
oxide. Similarly,  in  mining  and  sapping  work,  the  carbon  mon- 
oxide liberated  by  the  detonation  of  high  explosives  constitutes 
one  of  the  most  serious  of  the  difficulties  connected  with  this 

190 


CARBON   MONOXIDE  191 

work  and  necessitated  elaborate  equipment  and  extensive  mili- 
tary training  in  mine  rescue  work. 

The  removal  of  carbon  monoxide  from  the  air  is  difficult 
because  of  its  physical  and  chemical  properties.  Its  low  boiling 
point  and  critical  temperature  makes  adequate  adsorption  at 
ordinary  temperatures  by  the  use  of  an  active  absorbent  out  of 
the  question.  Its  known  insolubility  in  all  solvents  similarly  pre- 
cludes its  removal  by  physical  absorption. 

After  extensive  investigation  two  absorbents  have  been 
found.^  The  first  of  these  consists  in  a  mixture  of  iodine  pent- 
oxide  and  fuming  sulfuric  acid,  with  pumice  stone  as  a  carrier. 
Using  a  layer  10  cm.  deep  and  passing  a  1  per  cent  carbon 
monoxide  air  mixture  at  the  rate  of  500  cc.  per  minute  per  sq.  cm. 
cross  section,  a  100% -90%  removal  of  the  gas  could  be  secured 
for  two  hours  at  room  temperature  and  almost  as  long  at  0°  C. 
The  reaction  is  not  instantaneous,  and  a  brief  induction  period 
always  occurs.  This  may  be  reduced  to  a  minimum  by  the 
addition  of  a  little  iodine  to  the  original  mixture. 

The  sulfur  trioxide  given  off  is  very  irritating  to  the  lungs, 
but  by  the  use  of  a  layer  of  active  charcoal  beyond  the  carbon 
monoxide  absorbent,  this  disadvantage  was  almost  completely 
eliminated.  However,  sulfur  dioxide  is  slowly  formed  as  a 
result  of  this  adsorption  and  after  prolonged  standing  or  long 
continued  use  of  the  canister  at  a  high  rate  of  gas  flow  gives 
serious  trouble. 

Considerable  heat  is  given  off  in  the  reaction  and  a  cooling 
attachment  was  required.  The  most  satisfactory  device  was  a 
metal  box  filled  with  fused  sodium  thiosulfate  pentahydrate, 
which  absorbed  a  very  considerable  amount  of  the  heat. 

Still  a  further  disadvantage  was  the  fact  that  the  adsorbents 
became  spent  by  use,  even  in  the  absence  of  carbon  monoxide, 
since  it  absorbed  enough  moisture  from  the  air  of  average 
humidity  in  several  hours,  to  destroy  its  activity. 

The  difficulties  mentioned  were  so  troublesome  that  this  ab- 
sorbent was  finally  supplanted  by  the  more  satisfactory  oxide 
absorbent  described  below. 

The  metallic    oxide   mixture   was   the   direct   result   of   an 

*  Complete  details  of  this  work  may  be  found  in  J.  Ind.  Eiig.  Chem.,  12, 
21.3    (1920). 


192 


CHEMICAL  WARFARE 


observation  that  specially  precipitated  copper  oxide  with  1  per 
cent  silver  oxide  was  an  efficient  catalyst  for  the  oxidation  of 
arsine  by  oxygen.  After  a  study  of  various  oxide  mixtures, 
it  was  found  that  a  mixture  of  manganese  dioxide  and  silver 
oxide,  or  a  three  component  system  containing  cobaltic  oxide, 
manganese  dioxide  and  silver  oxide  in  the  proportion  of  20 :34 :46 
catalyzed  the  reaction  of  carbon  monoxide  at  room  temperature. 
The  studies  were  extended  and  it  was  soon  found  that  the  best 
catalysts  contained  active  manganese  dioxide  as  the  chief  con- 


Spcc'al  Small  Spring 

10  Mesh  Heavy  Iron  Screen 
1  Lajei  Cutton  Pad 


1^  Mesh  Heavy  Corrugated 
Iron  Screen 


Light  Fine  Mesh 
Coppur  Screen 


Heavy  Iron  Dome  Screen 
IC  Mesh 


Fig.  39. — Diagram  of  Carbon  Monoxide  Canister,  CMA3. 


stituent.  This  was  prepared  by  the  reaction  between  potassium 
permanganate  and  anhydrous  manganese  sulfate  in  the  presence 
of  fairly  concentrated  sulfuric  acid.  It  also  developed  that  the 
minimum  silver  oxide  content  decreased  progressively  as  the 
number  of  components  increased  from  2  to  4.  The  standard 
catalyst  (Hopcalite)  finally  adopted  for  production  consisted  of 
50  per  cent  manganese  dioxide,  30  per  cent  copper  oxide,  15  per 
cent  cobaltic  oxide  and  5  per  cent  silver  oxide.  The  mixture  was 
prepared  by  precipitating  and  washing  the  first  three  oxides 


CARBON  MONOXIDE 


193 


separately,  and  then  precipitating  the  silver  oxide  in  the  mixed 
sludge.  After  washing,  this  sludge  was  run  through  a  filter 
press,  kneaded  in  a  machine,  the  cake  dried  and  ground  to  size. 
While  it  is  not  difficult  to  obtain  a  product  which  is  catalytically 
active,  it  requires  a  vigorous  control  of  all  the  conditions  and 
operations  to  assure  a  product  at  once  active,  hard,  dense  and 
resistant  as  possible  to  the  deleterious  action  of  water  vapor. 
Hopcalite    acts    catalytically    and    therefore    only    a    layer 


Fig.  40. — Tanks  and  Press  for  Small  Scale  Manufacture  of  Carbon  Monoxide 

Absorbent. 

sufficiently  deep  to  insure  close  contact  of  all  the  air  with  the 
catalyst  is  needed.  One  and  a  half  inches  (310  gm.)  were  found 
ample  for  this  purpose. 

The  normal  activity  of  Hopcalite  requires  a  dry  gas  mixture. 
This  was  secured  by  placing  a  three-inch  layer  of  dry  granular 
calcium  chloride  at  the  inlet  side  of  the  canister. 

Because  of  the  evolution  of  heat,  a  cooling  arrangement  was 

o  used  in  the  Hopcalite  canisters. 

The  life  of  this  canister  was  the  same  irrespective  of  whether 
S  use  was  continuous  or  intermittent.     The  higher  the  tem- 


^^S 


194 


CHEMICAL  WARFARE 


perature  the  longer  the  life  because  Hopcalite  is  less  sensitive  to" 
water  vapors  at  higher  temperatures.  Since,  if  the  effluent  air 
was  sufficiently  dried,  the  Hopcalite  should  function  indefinitely 
against  any  concentration  of  carbon  monoxide,  Ihe  life  of  the 
canister  is  limited  solely  by  the  life  of  the  drier.  Therefore  the 
net  gain  in  weight  is  a  sure  criterion  of  its  condition.     After 


Fig.  41. — Navy  Head  Mask  and  Canister. 

many  tests  it  was  determined  that  any  canister  which  had  gained 
more  than  35  grams  above  its  original  weight  should  be  with- 
drawn. The  canisters,  at  the  time  of  breakdown,  showed  a  gain 
in  weight  varying  between  42  and  71  grams,  with  a  average  of 
54  grams.  It  is  really,  therefore,  the  actual  humidity  of  the 
air  in  which  the  canister  is  used  that  determines  its  life. 


CHAPTER  XI 1 
DEVELOPMENT  OF  THE  GAS  MASK 

While  in  ordinary  warfare  the  best  defense  against  any 
implement  of  war  is  a  vigorous  offense  with  the  same  weapon, 
Chemical  Warfare  presents  a  new  point  of  view.  Here  it  is 
very  important  to  make  use  of  all  defensive  measures  against 
attack.  Because  of  the  nature  of  the  materials  used,  it  has  been 
found  possible  to  furnish,  not  only  general  protection,  but  also 
continuous  protection  during  the  time  the  gas  is  present. 

The  first  consideration  in  the  protection  of  troops  against  a 
gas  attack  is  the  provision  of  an  efficient  individual  protective 
appliance  for  each  soldier.  The  gas  attack  of  April  22,  1915 
found  the  Allies  entirely  unprepared  and  unprotected  against 
poisonous  gas.  While  a  few  of  the  men  had  the  presence  of  mind 
to  protect  themselves  by  covering  their  faces  with  wet  cloths,  the 
majority  of  them  became  casualties.  Immediately  steps  were 
taken  to  improvise  protective  devices  among  which  were  gags, 
made  with  rags  soaked  in  water  or  washing  soda  solution,  hand- 
kerchiefs filled  with  moist  earth,  etc.  One  suggestion  w^as  to  use 
bottles  with  the  bottom  knocked  off  and  filled  with  moist  earth. 
The  breath  was  to  be  taken  in  through  the  bottle  and  let  out 
through  the  nose;  but  as  bottles  were  scarce  and  few  of  them 
survived  the  attempt  to  get  the  bottom  broken  off,  the  idea  was 
of  no  value. 

The  first  masks  were  made  by  the  women  of  England  in 
response  to  the  appeal  by  Lord  Kitchener;  they  consisted  of 
cotton  wool  wrapped  in  muslin  or  veiling  and  were  to  be  kept 
moist  with  water,  soda  solution  or  hypo. 

English  Masks 

The  Black  Veiling  Respirator.  The  first  form  of  the  Eng- 
lish mask  is  known  as  the  Black  Veiling  respirator  and  con- 

195 


193  CHEMICAL  WARFARE 

sisted  of  cotton  waste  enclosed  in  a  length  of  black  veiling.    The 
waste  was  soaked  in  a  solution  of: 

Sodium  thiosulphate 10      lbs. 

Washing  soda 2.5  lbs. 

Glycerine 2     lbs. 

Water 2      gals. 

The  glycerine  was  put  in  to  keep  the  respirator  moist,  thus 
obviating  the  need  for  dipping  before  use. 

The  respirator  was  adjusted  over  the  mouth  and  nose,  the 
cotton  waste  being  molded  to  the  shape  of  the  face  and  the 


Fig.  42. — Early  Gas  Protection. 

upper  edge  of  the  veiling  pulled  up  so  as  to  protect  the  eyes. 
These  respirators  were  used  in  the  attacks  of  May  10th  and  12th, 
1915  and  were  reasonably  efficient  against  the  low  concentration 
of  chlorine  then  used;  they  were  difficult  to  fit  exactly  to  the 
face,  which  resulted  in  leakage.  The  cotton  waste  often  became 
lumpy  and  had  to  be  shredded  out  or  discarded. 

The  Hypo  Helmet.  The  next  development  of  the  British 
protection  was  the  so-called  Hypo  helmet.  This  is  said  to  have 
resulted  from  the  suggestion  of  a  Canadian  sergeant  that  he  had 
seen  a  German  pulling  a  bag  over  his  head  during  a  gas  attack. 
It  consisted  of  a  flannel  bag  soaked  in  the  same  solution  as  was 


DEVELOPMENT  OF  THE  GAS  MASK  197 

used  for  the  veiling  respirator  and  was  fitted  with  a  pane  of  mica 
as  a  window.  The  helmet  was  tucked  down  inside  the  jacket 
which  was  then  buttoned  up  tightly  around  the  neck.  As  may 
be  seen  from  Figure  43,  this  would  not  prove  very  satisfactory 
with  the  American  type  of  uniform. 

This  helmet  had  many  advantages  over  the  veiling  respirator 
but  the  window  often  became  cracked  or  broken  from  the  rough 
treatment  in  the  trenches.  Later  the  mica  was  replaced  by 
celluloid  and  still  later  by  glass  eye-pieces  set  in  metal  rings. 
These  were  very  effective  against  chlorine  in  the  field. 

The  P  and  PH  Helmets.  During  the  summer  of  1915  it 
became  evident  that  phosgene-chlorine  mixtures  would  be  used  in 
gas  attacks  and  it  was  therefore  necessary  to  provide  protection 
against  this.  The  hypo  helmet,  which  offered  no  protection 
against  phosgene,  was  soaked  in  an  alkaline  solution  of  sodium 
phenolate  (carbolic  acid)  containing  glycerine,  and  with  this  new 
form  of  impregnation  was  called  the  P  helmet.  It  protected 
against  300  parts  of  phosgene  in  a  million  of  air.  Since  this 
solution  attacks  flannel,  two  layers  of  flannelette  were  used.  The 
helmet  was  further  improved  by  the  addition  of  an  expiratory 
valve,  partly  to  prevent  the  man  from  breathing  any  of  his  own 
breath  over  again  and  partly  to  prevent  the  deterioration  of  the 
alkali  of  the  mask  by  the  carbon  dioxide  of  the  expired  air. 

The  protection  was  later  further  increased  by  the  addition  of 
hexamethylenetetramine,  and  this  mask  is  known  as  the  PH 
helmet.    This  increased  the  protection  to  1,000  p.p.m. 

The  early  types  of  helmet  offered  no  protection  against 
lachrymators.  For  this  purpose  goggles  were  used,  the  later 
types  of  which  had  glass  eyepieces  and  were  fitted  around  the 
eyes  by  means  of  rubber  sponge.  While  intended  for  use  only 
after  a  lachrymatory  bombardment,  the  troops  frequently  used 
them  during  and  after  an  ordinary  gas  attack  when  the  mask 
should  have  been  worn.    Consequently  they  were  withdrawn. 

The  PH  helmet  was  unsatisfactory  because  of  the  following 
reasons ; 

(1)  It  was  warm  and  stuffy  in  summer; 

(2)  It  deteriorated  upon  exposure  to  air; 

(3)  It  was  incapable  of  further  development; 


198 


CHEMICAL   WARFARE 


(4)  It  had  a  peculiar  odor  and,  when  wet,  frequently  burned 
the  foreheads  of  the  men ; 

(5)  It  offered  practically  no  protection  against  lachry- 
mators. 

Box  Respirator.  The  increasing  concentration  of  gas  from 
cylinder  attacks  and  the  introduction  of  shell,  with  such  gases  as 
chloropicrin  and  superpalite,  led,  early  in  1916,  to  very  definite 


.«f 

"1 

•^ 

'Qi 

^ 

A 

^y 

^' 

ij 

1 

1 

1 

Fig.  43. — Method  of  Wearing  the 
P.  H.  Helmet. 


Fig.  44. — Early  Type  of  Standard 
(British)  Box  Respirator  (S.  B.  R.) 


and  constructive  efforts  on  the  part  of  the  British  to  increase  the 
protection  offered  by  the  mask.  The  result  was  a  ''polyvalent" 
respirator  of  the  canister  type  (the  Standard  Box  Respirator). 
This  mask  was  probably  the  result  of  experience  with  oxygen 
apparatus  in  mine  rescue  work.  The  lines  on  which  this  canister 
was  modeled  involved  the  use  of  a  canister  filled  with  highly 
sensitive  absorbent  charcoal  mixed  with  or  alternating  in  layers 
with  oxidizing  granules  of  alkaline  permanganate.  It  was  the 
result  of  innumerable  experiments,  partly  conducted  in  France 
but  mostly  in  England  under  the  direction  of  the  late  Lieut.  Col, 


DEVEI^OPMENT  OF  THE  GAS  MASK  199 

Harrison,  who  was  almost  entirely  responsible  for  the  wonderful 
production  of  this  respirator. 

The  respirator  (Figure  44)  consisted  of  the  canister  men- 
tioned above,  which  is  attached  by  a  flexible  tube  to  a  f  acepiece 
or  mask.  The  f acepiece  is  made  of  rubberized  fabric  and  fits  the 
face  so  that  there  is  little  or  no  leakage.  This  is  secured  by 
means  of  tape  and  elastic  bands  which  fit  over  the  head.  The 
nose  is  closed  by  means  of  clips,  which  are  wire  springs  with 
rubbered  jaws  covered  with  gauze  (Fig.  45).  Breathing  is 
done  through  a  mouthpiece  of  rubber;  the  teeth  close  on  the 
rubber  tabs  and  the  rubber  flange  lies  between  the  teeth  and  the 
lips.  The  expired  air  finds  exit  through  a  rubber  flutter  valve 
in  an  angle  tube  just  outside  the  mask.  This  arrangement 
furnishes  a  double  line  of  protection ;  if  the  face  piece  is  punc- 
tured or  torn,  gas-containing  air  cannot  be  breathed  as  long  as 
the  nose  clip  and  mouthpiece  are  in  position. 

The  early  English  canister  was  packed  with  675  cc.  of  8-14 
mesh  war  gas  mixture,  40  per  cent  of  which  was  wood  charcoal 
and  60  per  cent  reddish  brown  soda-lime  granules.  -  The  metal 
dome  at  the  bottom  of  the  can  was  covered  with  a  thin  film  of 
cotton.  At  two-thirds  of  the  distance  to  the  top  was  placed  a 
paper  filter  and  a  heavy  wire  screen  which  differs  from  our 
heavy  screen  in  that  it  is  more  loosely  woven.  The  mixture  was 
covered  with  a  cotton  filter  pad  and  a  wire  screen,  over  which 
was  placed  the  wire  spring. 

The  use  of  this  mask  ensures  that  all  the  air  breathed  must 
enter  the  lungs  through  the  canister.  This  air  passage  is  entirely 
independent  of  leaks  in  the  facepiece,  due  either  to  a  poor  fit 
about  the  face  or  to  actual  leakage  (from  a  cut  or  tear)  of  the 
fabric  itself.  The  facepiece  is  readily  cleared  of  poison  gases 
which  may  leak  in.  This  is  accomplished  by  taking  a  full 
inspiration,  releasing  the  noseclip,  and  exhaling  through  the 
nose,  which  forces  the  air  out  around  the  edges  of  the  facepiece. 

On  the  other  hand,  this  type  of  mask  possesses  a  number  of 
very  obvious  disadvantages,  particularly  from  a  military  point 
of  view : 

The  extreme  discomfort  of  the  facepiece.  This  discomfort 
arises  from  a  number  of  causes  certain  of  which  are  inherent  in 
this  type  of  mask,  among  them  being:  (a)  the  noseclip,  (&)  the 


200 


CHEMICAL  WARFARE 


mouthpiece,  and  (c)  the  lack  of  ventilation  within  the  facepiece 
chamber. 

Aside  from  the  actual  physical  discomfort  of  the  noseclip  and 
mouthpiece,  which  becomes  intense  after  long  periods  of  wearing, 
this  combination  forces  upon  the  wearer  an  unnatural  method  of 
respiration  to  which  it  is  not  only  difficult  to  become  accustomed, 
but  which  also  causes  extreme  dryness  of  the  throat.  The 
mouthpiece   greatly  increases  salivation   and   as   swallowing  is 


Fig.  45. — Interior  of  S.  B.  R.,  Showing 
Cotton  Wrapped  Nose  Chps. 


Fig.  46.— French  M-2  Mask. 


rather  more  difficult  with  the  nose  closed,  this  adds  another 
extremely  objectionable  feature. 

The  lack  of  ventilation  in  the  facepiece  chamber  entraps 
the  heat  radiating  from  the  face  and  retains  the  moisture 
v/hich  is  constantly  evaporating  from  the  skin.  This  moisture 
condenses  on  the  eyepieces,  and  even  if  cleared  away  by  the 
use  of  a  so-called  anti-dimming  paste,  usually  makes  vision 
nearly  impossible. 


DEVELOPMENT  OF  THE  GAS  MASK  201 

French  Masks 

M-2  Mask.  The  early  protection  of  the  French  Army  was 
obtained  from  a  mask  of  the  type  M-2  (Fig.  46). 

This  mask  consists  of  a  number  of  layers  of  muslin  impreg- 
nated with  various  absorbent  chemicals.  A  typical  mask  was 
made  up  of  20  layers  of  cheese-cloth  impregnated  with  Greasene 
and  20  layers  impregnated  with  Complexene.  These  solutions 
were  made  up  as  follows : 


Complexene : 

39.0  lbs. 

Hexamethylenetetramine 

37.5  lbs. 

Glycerine 

27.5  lbs. 

Nickel  sulfate  (NiS04.7  H2O) 

11.8  lbs. 

Sodium  carbonate  (Na2  CO3) 
Water 

Greasene : 

107.0  lbs. 

Castor  oil 

81.0  lbs. 

Alcohol  (95%) 

10.7  lbs. 

-  Glycerine  (90%) 

3.1  lbs. 

Sodium  hydroxide  (NaOH) 

This  mask  fits  the  face  tightly  and  as  a  consequence  the 
inhaled  air  can  be  obtained  only  by  drawing  it  through  the 
pores  of  the  impregnated  fabric.  There  is  no  outlet  valve. 
The  exhaled  air  makes  its  escape  through  the  fabric.  The 
eyepieces  are  made  of  a  special  non-dimming  celluloid.  The 
mask  is  protected  from  rain  by  a  flap  of  weather  proof  fabric, 
which  also  protects  the  absorbent  chemicals  from  deterioration. 

At  the  beginning  of  the  war  the  United  States  experimented 
considerably  with  the  French  mask.  Several  modifications  of 
the  impregnating  solutions  were  suggested,  as  well  as  methods 
of  application.  One  of  these  was  to  separate  the  components 
of  the  complexene  solution  and  impregnate  two  separate  layers 
of  cloth;  this  would  make  a  three-layer  mask.  In  view  of 
the  phosgene  which  was  in  use  at  that  time,  the  following 
arrangement  was  suggested: 

20  layers  of  hexamethylenetetramine, 

10  layers  of  nickel  sulfate-sodium  carbonate, 

10  layers  of  greasene. 

This  arrangement  was  more  effective  than  the  original  French 
mask  and  offered  the  following  protection  when  tested  against 


202  CHEMICAL  WARFARE 

the  following  gases   (concentration  1  to  1,000,  rate  30  liters 
per  minute)  : 

Phosgene * 65  minutes 

Hydrocyanic  acid 60  minutes 

Chlorine    60  minutes 

Tissot  Mask.     The  French  deserve  great  credit  for  their 
development  of  the  Tissot  type  mask.     This  was  first  issued 


Fig.  47. — Interior  View  of  M-2 
Mask. 


Fig.  48. — French  Artillery  Mask, 
Tissot  Type. 


to  artillerymen,  stretcher  bearers,  and  certain  other  special 
classes  of  soldiers  to  furnish  them  with  protection  and  yet 
enable  them  to  work  with  greater  efficiency  because  of  the 
decrease  in  resistance  to  breathing.  The  mask  (Fig.  48) 
resembles  the  British  box  respirator  in  that  it  consists  of  a 
canister  and  rubber  facepiece,  but  differs  in  that  the  mouth- 
piece and  noseclip  are  lacking.  The  inhaled  air  enters  the 
mask  from  two  tubes  which  open  directly  under  the  eyepieces 


DEVELOPMENT  OF  THE  GAS  MASK  203 

and  allow  the  air  to  sweep  across  them.  This  removes,  by 
evaporation,  the  condensed  moisture  of  the  breath  from  the 
eyepieces,  which  otherwise  would  obstruct  the  vision.  The 
circulation  of  the  fresh  air  in  the  mask  also  removes  and 
dilutes  lachrymatory  gases  which  may  filter  through  the  mask. 
The  exhaled  air  escapes  through  a  simple  outlet  valve.  This 
type  of  mask  is  advantageous  because: 

(1)  The  facepiece  is  tight  and  comfortable. 

(2)  The  eyepieces  do  not  become  dimmed. 

(3)  There  is  no  difficulty  in  speaking. 

(4)  Salivation  is  eliminated  because  of  the  absence  of  the 
mouthpiece. 

(5)  It  is  generally  more  comfortable  than  the  box  respi- 
rator. 

This  mask,  however,  was  made  of  thin  rubber  of  great 
flexibility  which,  while  affording  a  perfect  fit,  did  not  possess 
sufficient  durability  to  recommend  it  as  the  sole  defense  of 
the  wearer. 

The  canister  is  markedly  different  from  all  other  canisters 
described  in  this  chapter  in  that  a  highly  hygroscopic  chemical 
absorbent  is  used.  An  approximate  determination  showed 
about  70  per  cent  sodium  hydroxide.  The  use  of  caustic  soda 
in  the  canister  is  made  possible  by  the  intermixing  of  steel 
wool  with  the  granules  of  caustic.  A  layer  of  absorbent  having 
the  appearance  of  vegetable  charcoal  is  placed  at  the  top  of 
the  canister. 

The  canister  has  the  shape  of  a  rectangular  prism 
^  X  61/^  X  21/^  inches ;  and,  owing  to  the  use  of  steel  wool, 
is  large  in  proportion  to  the  weight  of  absorbent  contained. 
Valves  are  supplied  which  prevent  exhalation  through  the 
canister.  When  not  in  use  the  opening  in  the  bottom  of  the 
canister  is  plugged  with  a  rubber  stopper  to  protect  the 
absorbents  from  moisture.  The  canister  is  carried  against 
the  body  and  is  connected  to  the  facepiece  with  a  flexible 
rubber-fabric  tube. 

A.  R.  S.  Mask  (Appareil  Respiratoire  Special).  One  of  the 
latest  types  of  French  mask  is  the  so-called  A.  R.  S.  mask, 
which  is  based  upon,  or  at  least  resembles  closely,  the  German 


204 


CHEMICAL  WARFARE 


mask.  This  is  a  frame  mask  made  from  well  rubberized  balloon 
material,  provided  on  the  inside  with  a  lining  of  oiled  or 
waxed  linen  and  fitted  with  a  drum  which  is  screwed  on.  The 
mask  is  provided  with  eyepieces  of  cellophane,  fastened  by- 
metal  rings  into  rubber  goggles,  which  are  sewed  in  the  mask. 
A  metal  mouth-ring  is  tied  in  the  mask  with  tape.  This  ring 
is  placed  somewhat  higher  than  in  the  German  mask,  in  this 


Fig.  49.— French  A.  R.  S.  Mask. 


way  reducing  the  harmful  space  under  the  mask.  An  inlet 
and  outlet  valve  is  placed  in  the  mouth-ring;  the  first  is  of 
mica  while  the  other,  which  is  in  direct  communication  with 
the  interior  of  the  mask,  is  of  rubber.  On  the  inside  of  the 
mask,  in  front  of  the  valves,  a  baffle  is  sewed  in,  whereby 
the  inhaled  air  is  forced  to  pass  in  front  of  the  eyepieces  to 
prevent  dimming  and,  at  the  same  time,  condensed  vapor  is 
prevented  from  entering  the  valves. 

The  mask  or  head  straps  are  arranged  in  the  same  way 


DEVELOPMENT  OF  THE  GAS  MASK  205 

as  on  the  latest  M-2  mask,  i.e.,  one  elastic  band  is  placed  across 
the  top  of  the  head  and  the  other  across  the  back;  the  two 
are  joined  by  an  elastic.  Below  these  two  straps  is  an  adjust- 
able elastic  neck  band.  The  drum  is  made  of  metal  similar, 
in  shape  to  the  German  drum  and  fits  in  the  mouth-ring  by- 
means  of  a  thread.  It  is  made  tight  by  a  rubber  ring  as  in  the 
German  mask.  The  thread  differs  from  that  on  the  German 
mask,  making  an  interchange  of  canisters  impossible.  The 
canister  or  drum  includes  a  bottom  screen,  springs  and  wire 
screens  between  the  layers.  It  is  closed  by  a  perforated  bottom. 
There  are  three  layers.  On  the  top  is  a  thin  layer  of  absorbent 
cotton.  Beneath  this  is  a  central  layer  of  charcoal,  which 
is  a  little  finer  than  the  German  charcoal.  The  lower  layer 
consists  of  soda-lime,  mixed  with  charcoal  and  zinc  oxide  and 
moistened  with  glycerine. 

German  Mask 

The  early  type  of  German  mask  probably  served  as  the 
model  for  the  French  A.  R.  S.  mask.  The  facepiece  was  made 
of  rubber,  which  was  later  replaced  by  leather  because  of  the 
shortage  of  rubber.  The  following  is  a  good  description  of 
a  typical  German  facepiece: 

**The  facepiece  of  the  German  mask  was  made  of  one  piece 
of  leather,  with  seams  at  the  chin  and  at  the  temples,  giving 
it  roughly  the  shape  of  the  face.  The  leather  was  treated  with 
oil  to  make  it  soft  and  pliable,  also  to  render  it  impervious 
to  gases.  The  dressed  surface  was  toward  the  inside  9f  the 
mask.  A  circular  steel  plate,  3  inches  in  diameter,  was  set 
into  the  facepiece  just  opposite  the  wearer's  nose  and  mouth, 
with  a  threaded  socket  into  which  the  drum  containing  the 
absorbents  screwed.  A  rubber  gasket  (synthetic?)  held  in 
place  by  a  sort  of  pitch  cement,  secured  a  gas-tight  joint 
between  the  drum  and  the  facepiece.  There  were  no  valves, 
both. inhaled  and  exhaled  air  passing  through  the  canister. 
The  eyepieces  were  inserted  by  means  of  metal  rims  with 
leather  washers,  and  were  in  two  parts:  (a)  a  permanent 
exterior  sheet  of  transparent  material  (*cellon')  resembling 
celluloid,  and   (6)   an  inner  removable  disc  which  functioned 


206 


CHEMICAL  WARFARE 


as  an  anti-dimming  device.  This  latter  appeared  to  be  of 
'cellon'  coated  on  the  side  toward  the  eye  with  gelatin,  and 
was  held  in  position  by  a  'wheel'  stamped  from  thin  sheet 
metal,  which  screwed  into  the  metal  rim  of  the  eyepiece  from 
the  inside.  The  gelatin  prevented  dimming  by  absorbing  the 
moisture,  but  wrinkled  and  blistered  and  became  opaque  after 


Fig.  50. — German  Respirator. 

a  few  hours'  use,  and  could  not  be  changed  without  removing 
the  mask.  The  edge  of  the  facepiece  all  around  was  provided 
with  a  bearing  surface  consisting  of  a  welt  of  finely  woven 
cloth  about  one  inch  wide  sewed  to  the  leather.  In  some 
instances  this  welt  was  of  leather  of  an  inferior  grade.  The 
edge  of  the  facepiece  was  smoothed  over  by  a  coat  of  flexible 
transparent  gum,  probably  a  synthetic  compound." 


DEVEWPMENT  OF  THE  GAS  MASK 


207 


fl  S  9  rt  b 
I  CJ  «  -<  O 
»-<  ei  eo  ■^'  lo 


208 


CHEMICAL  WARFARE 


German  Canister.  The  general  appearance  of  the  canister 
(Sept.,  1916  Type)  is  that  of  a  short  thick  cylinder  slightly 
tapered  and  having  at  the  smaller  end  a  threaded  protrusion 
or  neck  by  which  it  is  screwed  onto  the  facepiece.  The  cylinder 
is  about  10  cm.  in  diameter  and  about  5  cm.  in  length.  In  the 
canister  are  three  layers  of  absorbents  of  unequal  thickness 
separated  by  disks  of  fine  mesh  metal  screen.  The  canister  is 
shipped  in  a  light  sheet  iron  can  10  cm.  in  diameter  and  8  cm. 


Fig.  52. — Cross  Section  of  1917  and  1918  German  Canisters. 


Absorbents. 

Absorbent. 

Composition. 

Weight. 

Volume. 

1917.    No.  1. 

Chemical  Absorbent. 

66  gr. 

105  cc. 

No.  2. 

Impregnated  Charcoal. 

36  gr. 

85  cc. 

No.  3. 

Chemical  Absorbent. 

15  gr. 

45  cc. 

1918.    No.  1. 

Impregnated  Charcoal. 

58  gr. 

185  cc. 

No.  2. 

Chemical  Absorbent. 

29  gr. 

45  cc. 

Total  Volume  of  Absorbents,  1917,  235  cc.  =  14.3  cu.  in. 

1918,  230  cc.  =  14.0  cu.  in. 
Total  Weight  of  Absorbents,     1917,  117  gr. 

1918,     87  gr. 
Volume  of  Air  Space  above  Absorbents  =  50  cc.=3.1  cu.  in. 


high.  The  can  is  shellacked  and  is  lined  with  paper  packing 
board.  The  container  is  made  air-tight  by  sealing  with  a  strip 
of  adhesive  tape. 

Body.  The  body  of  the  canister  is  made  of  sheet  metal 
(probably  iron),  which  is  protected  on  the  outside  with  a  coat 
of  dark  gray  paint  and  on  the  inside  with  a  japan  varnish. 
For  ease  in  assembling  the  sides  of  the  canister  have  a  gentle 
taper,  and  are  formed  so  as  to  supply  a  seat  for  each  of  the 
follower  rings.  The  protrusion  or  neck  has  about  six  threads 
to  the  inch,  the  pitch  of  the  screw  being  4  mm.    The  lower  part 


DEVELOPMENT  OF  THE  GAS  MASK  2C9 

the  body  is  rolled  so  as  to  give  a  finished  edge,  and  the  upper 
part  of  the  cylinder  is  grooved  to  receive  the  top  support. 

The  first  screen  is  double,  consisting  of  a  coarse  top  screen 
five  to  six  mesh,  per  linear  inch,  and  immediately  below,  a 
finer  screen  of  30-40  mesh,  per  linear,  inch.  The  top  support 
is  a  rigid  ring  of  metal  with  two  cross  arms,  which  give  added 
strength  to  the  ring  and  support  to  the  screens.  It  springs 
into  a  groove  at  the  top  of  the  body  and  forms  the  support 
for  the  contents  of  the  canister.  Both  screens  are  made  of  iron 
wire  and  the  top  support  is  made  of  iron  (probably  lightly 
tinned). 

The  second  screen,  which  separates  the  second  and  third 
absorbents,  is  double,  consisting  of  two  disks  of  30-^0  mesh 
iron  screen.    Both  screens  are  held  in  place  by  a  follower  ring. 

The  third  screen  is  single,  but  otherwise  it  is  exactly  similar 
to  the  second  screen.  It  serves  to  keep  separate  the  layers  of 
absorbents  No.  1  and  No.  2. 

The  fourth  screen  (30-40  mesh)  is  made  of  iron  wire  and 
is  held  to  the  bottom  support  by  six  cleats  which  are  punched 
from  the  body  of  the  support.  The  bottom  support  is  simply 
a  flanged  iron  cover  for  the  bottom  of  the  canister.  It  is 
punched  with  79  circular  holes  each  4  mm.  in  diameter  and 
is  painted  on  the  outside  to  match  the  body  of  the  canister. 
The  screen  and  the  inside  of  the  bottom  support  or  cover  are 
coated  with  a  red  paint. 

I  At  the  entrance  of  the  United  States  into  the  war,  three 
es  of  masks  were  available:  the  PH  helmet,  the  British 
S.  B.  R.  and  the  French  M-2  masks.  Experiments  were  made 
on  all  three  of  these  types,  and  it  was  soon  found  that  the 
S.  B.  R.  offered  the  greatest  possibilities,  both  as  regards 
immediate  protection  and  future  development.  During  the 
eighteen  months  which  were  devoted  to  improvement  of  the 
American  mask,  the  facepiece  underwent  a  gradual  evolution 
and  the  canister  passed  through  types  A  to  L,  with  many 
special  modifications  for  experimental  purposes.  The  latest 
development  consisted  in  an  adaptation  of  the  fighting  mask 


American  Mask 


210 


CHEMICAL   WARFARE 


to  industrial  purposes.  For  this  reason  a  rather  detailed 
description  of  the  construction  of  the  facepiece  and  of  the 
canister  of  the  respirator  in  use  at  the  close  of  the  war 
(R.  F.  K.  type)  may  not  be  out  of  place.  The  mask  now  adopted 
as  standard  for  the  U.  S.  Aarmy  and  Navy  is  known  as  the 
Model  1919  American  mask,  with  1920  model  carrier,  and  will 
be  described  on  page  225. 


Fig.  53. — Diagrammatic  Sketch  of  Box  Respirator  Type  Mask. 

Faoepiece.  The  facepiece  of  the  R.  F.  K.  type  Box  Respi- 
rator is  made  from  a  light  weight  cotton  fabric  coated  with 
pure  gum  rubber,  the  finished  fabric  having  a  total  thickness  of 
approximately  ^  inch.  The  fit  of  the  facepiece  is  along 
two  lines — first,  across  the  forehead,  approximately  from  tem- 
ple to  temple;  second,  from  the  same  temporal  points  down 
the  sides  of  the  face  just  in  front  of  the  ears  and  under  the 
chin  as  far  back  as  does  not  interfere  with  the  Adam's  apple. 
In  securing  this  fit,  the  piece  of  stock  for  the  facepiece  is 
died  out  of  the  felt  and  pleated  up  around  the  edges  to  con- 
form to  this  line.  After  this  pleating  operation,  the  edges  of 
the  fabric  are  stitched  to  a  binding  frame  similar  to  a  hat-band 
made  up  of  felt  or  velveteen  covered  with  rubberized  fabric. 


^aII  the  st] 


DEVELOPMENT  OF  THE  GAS  MASK  211 


b 


11  the  stitching  and  joints  in  the  facepiece  are  rendered  gas- 
tight  by  cementing  with  rubber  cement.  This  facepiece  is  made 
in  five  sizes  ranging  from  No.  1  to  No.  5,  with  a  large  majority 
of  faces  fitted  by  the  three  intermediate  sizes,  2,  3,  4. 

Harness.  The  function  of  the  harness  is  to  hold  the  mask 
on  the  face  in  sucli  a  way  as  to  insure  a  gas-tight  fit  at  all 
points.  Because  of  the  great  variations  in  the  conformation 
oL'  different  heads,  this  problem  is  not  a  simple  one.  Probably, 
the  simplest  type  of  harness,  as  well  as  the  one  which  is 
tlieoretically  correct,  consists  of  a  harness  in  which  the  line 
of  fit  across  the  forehead  is  extended  into  an  elastic  band 
passing  around  the  back  of  the  head,  while  the  line  of  fit 
around  the  side  of  the  face  and  chin  is  similarly  extended  into 
another  elastic  tape  passing  over  the  top  of  the  head;  these 
should  be  held  in  place  by  a  third  tape,  preferably  non-elastic, 
attached  to  the  mask  at  the  middle  of  the  forehead  and  to 
the  middle  points  of  the  other  tapes  at  a  suitable  distance  to 
liold  them  in  their  proper  positions. 

The  discomfort  of  the  earlier  types  of  harness  has  been 
lemedied,  in  a  large  measure,  by  the  development  of  a  specially 
woven  elastic  web  which,  for  a  given  change  in  tension,  allowed 
more  than  double  the  stretch  of  the  commercial  weaves.  There 
i>  still  much  room  for  valuable  work  in  developing  a  harness 

ich  will  combine  greater  comfort  and  safety.  The  following 
ints  should  always  be  observed  in  harness  design : 

(1)  The  straps   should  pull   in  such   a   direction  that  as 
rge  a  component  as  possible  of  the  tension  of  the  strap  should 

available  in  actually  holding  the  mask  against  the  .face. 

(2)  The  number  of  straps  should  be  kept  to  a  minimum 
order  to  avoid  tangling  and  improper  positioning  when  put 

in  a  hurry  by  an  inexperienced  wearer. 
Eyepieces.     One  of  the  most  important  parts  of  the  gas 
ask,  from  the  military  point  of  view,  is  the  eyepiece.     The 
imary  requirement  of  a  good  eyepiece  is  that  it  shall  provide 
minimum  reduction  in  clarity  of  vision  with  a  maximum 
gree  of  safety  to  the  wearer.    The  clarity  of  vision  may  be 
ffected  in  one  of  several  ways:  (1)  by  abrasion  of  the  eye- 
ieces  under  service  conditions;  (2)  irregularities  in  the  sur- 
face and  thickness  of  the  eyepiece,  causing  optical  dispersion; 


212  CHEMICAL  WARFARE 

(3)  absorption  of  light  by  the  eyepiece  itself;  (4)  dimming 
of  the  eyepieces  due  to  condensation  of  moisture  radiating 
from  the  face  or  in  the  exhaled  air. 

Three  types  of  eyepieces  were  used  but  by  the  end  of  the 
war  the  first  two  types  had  been  abandoned. 

(1)  Ordinary  celluloid. 

(2)  Various  hygroscopic  forms  of  celluloid,  known  as  non- 
dimming  eyepieces. 

(3)  Various  combinations  of  glass  and  celluloid,  known  as 
non-breakable  eyepieces. 

Celluloid  was  used  first,  due  to  its  freedom  from  breakage. 
It  is  not  satisfactory  because  it  is  rapidly  abraded  in  use,  turns 
yellow,  thus  increasing  its  light  absorption,  has  relatively  uneven 
optical  surfaces  and  becomes  brittle  after  service. 

The  various  forms  of  non-dimming  lenses  function  by  absorp- 
ing  the  water  which  condenses  on  their  surfaces,  either  by  com- 
bining individual  drops  into  a  film  which  does  not  seriously  im- 
pair vision,  by  transmitting  it  through  the  surface  and  giving 
it  off  on  the  exterior  or  by  a  combination  of  these  mechanisms. 
With  the  exception  that  they  are  non-dimming,  they  are  open 
to  all  the  Dbjections  of  the  celluloid  eyepiece  and,  as  a  matter  of 
fact,  were  never  tried  out  in  the  field. 

The  so-called  non-breakable  eyepieces  are  formed  by  cement- 
ing together  a  layer  of  celluloid  between  two  layers  of  glass.* 
This  results  in  an  almost  perfect  eyepiece.  Any  ordinary  blow 
falling  upon  such  an  eyepiece  does  no  more  than  crack  the 
glass,  which  remains  attached  to  the  celluloid  coating.  Except 
in  extreme  cases,  the  celluloid  remains  unbroken  and  there  is 
relatively  slight  danger  of  a  cracked  eyepiece  of  this  sort  leak- 
ing gas. 

In  the  matter  of  flying  fragments,  the  type  of  eyepiece  con- 
sisting of  a  single  layer  of  celluloid  and  glass  with  the  celluloid 
placed  next  to  the  eye,  has  probably  a  slight  advantage  over  the 
type  in  which  there  is  glass  on  both  sides.  However,  the  superior 
optical  surface  of  the  latter  type,  coupled  with  its  greater  free- 
dom from  abrasion  of  the  surface  led  to  the  adoption  of  this 
type  known  as  "triplexin"  in  the  mask  produced  in  the  later 
part  of  the  American  manufacturing  program.     It  should  be 

*  So-called  ' '  Triplex ' '  glass. 


DEVELOPMENT  OF  THE  GAS  MASK 


213 


pointed  out  in  connection  with  this  type  of  eyepiece  that  it  is 
possible  to  make  it  as  perfect  optically  as  desired  by  using  the 
better  grades  of  glass.  While  the  optical  properties  of  these 
eyepieces  undoubtedly  suffer  somewhat  with  age,  due  to  the  dis- 
coloration of  the  celluloid,  it  can  be  safely  said  that  this  material, 
located  as  it  is  between  the  layers  of  glass  and  relatively  little 
exposed  to  atmospheric  conditions,  will  probably  be  far  less 
affected  in  this  way  than  is  the  ordinary  celluloid  eyepiece. 


I 


K 


Fig.  54. — American  Box  Respirator,  Showing  Improved  Rubber  Nose  Clip. 

The  position  of  the  eyepiece  is  very  important ;  the  total  and 
e  binocular  fields  of  vision  should  be  kept  at  a  maximum. 
Nose-clip.  The  nose-clip  is  probably  the  most  uncomfortable 
feature  of  the  types  of  mask  used  during  the  War.  While  a 
really  comfortable  nose  pad  is  probably  impossible,  the  com- 
rt  of  the  clip  was  greatly  improved  by  using  pads  of  soft 
bber  and  springs  giving  the  minimum  tension  necessary  to 
elose  the  nostrils. 


214  CHEMICAL  WARFARE 

Mouthpiece.  The  design  of  the  mouthpiece  should  consider 
the  size  and  shape  of  the  flange  which  goes  between  the  lips  and 
teeth;  this  should  be  such  as  to  prevent  leakage  of  gas  into  the 
mouth  and  should  reduce  to  a  minimum  any  chafing  of  the  gums. 
The  opening  through  the  mouthpiece  is  held  distended  at  its 
inner  end  by  a  metallic  bushing  to  prevent  its  collapse,  if,  under 
stress  of  excitement,  the  jaws  are  forced  over  the  flange  and 
closed.  Rubber  has  proved  a  very  satisfactory  material  for  this 
part  of  the  facepiece. 

Flexible  Hose.  The  flexible  hose  leads  from  the  angle  tube 
to  the  canister.  This  should  combine  flexibility,  freedom  from 
collapse,  and  extreme  physical  ruggedness.  These  speciflcations 
are  met  successfully  by  the  stockinette-covered  corrugated  rubber 
hose.  The  angular  corrugations  not  only  give  a  high  degree  of 
flexibility  but  are  extremely  effective  in  preventing  collapse. 
The  flexibility  gained  by  this  construction  is  not  only  lateral 
but  also  longitudinal;  a  hose  having  a  nominal  length  of  10 
inches  functions  successfully  between  lengths  of  8  and  12  inches. 
The  covering  of  stockinette,  which  is  vulcanized  to  the  rubber  in 
the  manufacturing  process,  adds  materially  to  the  mechanical 
strength  by  preventing  incipient  tears  and  breaks. 

Exhalation  Valve.  The  exhalation  valve  allows  the  exhaled 
air  to  pass  directly  to  the  outside  atmosphere.  (This  valve  is 
not  found  on  the  German  mask.)  This  valve  has  the  following 
advantages : 

(1)  It  tends  to  reduce  very  materially  the  dead-air  space  in 
the  mask. 

(2)  It  prevents  deterioration  of  the  absorbent  on  account  of 
moisture  and  carbon  dioxide  of  the  expired  air. 

(3)  It  reduces  the  back  pressure  against  expiration,  since  it 
is  unnecessary  to  breathe  out  against  the  resistance  of  the 
canister. 

The  disadvantage,  which  may  under  certain  conditions  be 
very  serious,  is  that,  if  for  any  reason  the  valve  fails  to  function 
properly,  inspiration  will  take  place  through  the  valve.  It  can 
be  readily  seen  that,  any  failure  of  this  nature  will  allow  the 
poisonous  atmosphere  to  be  drawn  directly  into  the  lungs  of  the 
wearer. 

The  type  of  valve  generally  used  is  shown  in  Fig.  55,  which 


DEVELOPMENT  OF  THE  GAS  MASK 


215 


shows  one  of  these  valves  mounted  and  unmounted.  While  it  is 
rather  difficult  to  give  a  clear  description  of  its  construction,  the 
valve  may  be  considered  as  a  flattened  triangular  sack  of  rubber, 
whose  altitude  is  two  or  three  times  the  base  and  from  which 
all  three  corners  have  been  clipped,  each  giving  openings  into  the 
interior  of  the  sack.  The  opening  at  the  top  is  slipped  over  the 
exhalation  passage  of  the  angle  tube,  and  the  air  passes  out 
through  the  other  two  corners.  Closure  is  obtained  by  the  com- 
bination of  two  factors, — first,  the  difference  in  atmospheric 


Fig.  55. — American  Type  Exhale  Valve,  Mounted  and  Unmounted. 


pressure,  and  second,  the  tension  due  to  mounting  a  section 
which  has  been  cured  in  the  flat  over  an  elliptical  opening. 

In  order  to  protect  the  flutter  valve  from  injury  and  from 
contact  with  objects  which  might  interfere  with  its  proper  func- 

Itioning,  the  later  types  of  valve  were  provided  with  a  guard  of 
Stamped  sheet  metal. 
L 


Canisters 

During  the  development  of  the  facepiece,  as  discussed  above, 
le  American  canister  underwent  changes  in  design  which  have 


216 


CHEMICAL  WARFARE 


been  designated  as  A  to  L.     These  changes  were  noted  by  the 
different  colored  paints  applied  to  the  exterior  of  the  canister. 

Type  A  canister  was  exactly  like  the  British  model  then  in 
use,  except  that  it  was  made  one  inch  longer  because  it  was 
realized  that  the  early  absorbents  were  of  poor  quality.  The 
canister  was  made  of  beaded  tin  plate  and  was  18  cm.  high.  The 
area  of  the  flattened  oval  section  was  65  sq.  cm.  In  the  bottom 
was  a  fine  wire  dome  3.4  cm.  high.    The  valve  in  the  bottom  was 


aPatnt( 
L 


Painted  Black  all  over 


Charcoal 


Fig.  56. — American  Canister,  Type  A. 


integral  with  the  bottom  of  the  container,  there  being  no  remov- 
able plug  for  the  insertion  of  the  check  valve.  The  absorbents 
were  held  in  place  by  a  heavy  wire  screen  on  top  and  by  two 
rectangular  springs. 

Inhaled  air  entered  through  the  circular  valve  at  the  bottom 
of  the  canister,  passed  through  the  absorbents  and  through  a 
small  nipple  at  the  top. 

The  filling  consisted  of  60  per  cent  by  volume  of  wood  char- 
coal, developed  by  the  National  Carbon  Co.,  and  40  per  cent  of 
green  soda  lime,  developed  and  manufactured  by  the  General 


I 


DEVELOPMENT  OF  THE  GAS  MASK  217 


Chemical  Company,  Easton,  Pa.  The  entire  volume  amounted  to 
660  cc.  The  early  experiments  with  this  volume  of  absorbent 
showed  that  -/g  soda  lime  was  the  minimum  amount  that  could 
be  used  and  still  furnish  adequate  protection  against  the  then 
known  war  gases.  It  was,  therefore,  decided  to  use  ^/^  soda  lime 
and  ^/s  charcoal  by  volume  and  this  proportion  has  been  adhered 
to  in  all  of  the  later  types  of  canisters.  It  is  interesting  to  note 
that  these  figures  have  been  fully  substantiated  by  the  later 
experimental  work  on  canister  filling. 

The  charcoal  and  soda  lime  were  not  mixed  but  arranged  in 
five  layers  of  equal  volume,  each  layer,  therefore,  containing  20 
per  cent  of  the  total  volume.  The  layers  were  separated  by 
screens  of  crinoline.  At  the  top  was  inserted  a  layer  of  terry 
cloth,  a  layer  of  gray  flannel,  and  two  steel  wire  screens.  The 
cloth  kept  the  fine  particles  of  chemicals  from  being  drawn  into 
the  throat  of  the  person  wearing  the  ma^k. 

This  canister  furnished  very  good  protection  against  chlorine 
and  hydrocyanic  acid  and  was  fairly  efficient  against  phosgene, 
but  it  was  useless  against  chloropicrin.  These  canisters  were 
never  used  at  the  front,  but  served  a  very  useful  purpose  as 
experimental  canisters  and  in  training  troops. 

It  was  soon  found  that  better  protection  was  obtained  if  the 
absorbents  were  mixed  before  packing  in  the  canister.  This 
procedure  also  simplified  the  method  of  packing  and  was  used  in 
canister  B  and  following  types.  Among  other  changes  intro- 
duced in  later  types  were :  The  integral  valve  was  replaced  by 
a  removable  check  valve  plug  which  enabled  the  men  in  the  field 
to  adjust  the  valve  in  case  it  did  not  function  properly.  The 
mixture  of  charcoal  and  soda  lime  was  divided  into  three  sep- 
arate layers  and  these  separated  by  cotton  pads.  The  pads 
offered  protection  against  stannic  chloride  smokes  but  not  against 
smokes  of  the  type  of  sneezing  gas.  The  green  soda  lime  was 
replaced  by  the  pink  granules.  In  April,  1918,  the  mesh  of  the 
absorbent  was  changed  to  8  to  14  in  place  of  6  to  14. 

About  July  1,  1918,  the  authorities  were  convinced  by  the 
field  forces  of  the  Chemical  Warfare  Service  that  the  length  of 
life  of  the  chemical  protection  of  the  standard  H  canister  (the 
type  then  in  use)  was  excessive  and  that  the  resistance  was  much 
too  high.     Type  J  was  therefore  adopted,  July  27,  1918.     In 


218 


CHEMICAL  WARFARE 


f 


this  the  volume  of  the  absorbent  was  reduced  from  450  cc.  to 
300  CO.  It  was  packed  in  two  layers,  ^/g  in  the  bottom  and  ^/a 
in  the  top.  One  pad  was  placed  between  the  layers  and  one  on 
top.  This  change  gave  a  lowering  of  the  resistance  of  27  per 
cent  (to  2.5  inches)  at  a  sacrifice  of  50  per  cent  of  the  length  of 
life  of  the  canister,  but  not  of  protection  during  the  shortened 
life.  Type  L  differed  from  this  only  in  having  325  cc.  of  ab- 
sorbent, a  change  made  to  decrease  leakage  about  the  top  cotton 
pad. 


Spacer 

Spring 
Heavy  Screen 
Cotton  iLd 

Packing  Scr'.en 
PfJJ    Xottoji  I  i.d 


Screen 
Check  Valve 


Fig.  57.— U.  S.  Army  Canister,  Type  J. 

The  following  table  shows  the  relative  efficiency  of  various 
canisters : 


Chloropicrin .... 

Phosgene 

Hydrocyanic  acid 
Mustard  gas .... 


p.  p.  m. 


1000 

2500 

500 

100 


U.S., 
TypeH 


770 

85 

70 

1800 


British, 
S.  B.  R. 


17 
54 
90 


French, 
A.  R.  S. 


2 

5 

35 


German 


43 

16 

10 

195 


DEVELOPMENT  OF  THE  GAS  MASK 


219 


B 


220  CHEMICAL  WARFARE 

The  figures  represent  time  in  minutes  till  the  first  traces  of  gas 
begin  to  come  through. 


Manufacture 

The  following  description  of  the  manufacture  of  the  gas 
mask  at  the  Long  Island  plant  is  taken  from  an  article  by  Col. 
Bradley  Dewey^: 

"Incoming  Inspection — A  thorough  100  per  cent  inspection  was 
made  of  each  part  before  sending  it  to  the  Assembly  Department. 
The  inspectors  were  carefully  chosen  and  were  sent  to  a  school  for 
training  before  they  were  assigned  to  this  important  work.  Every 
feature  found  to  be  essential  to  the  manufacture  of  a  perfect  gas  mask 
was  carefully  checked. 

"The  incoming  inspection  of  the  flexible  rubber  hose  leading  from 
the  canister  to  the  facepieee  can  be  taken  as  an  illustration.  Each 
piece  of  hose  was  given  a  visual  inspection  for  buckles  or  blisters 
in  the  ends  or  in  the  corrugations;  for  cuts,  air  pockets,  or  other 
defects  on  the  interior;  for  loose  seams  where  fabric  covering  was 
cemented  to  the  rubber  tube;  for  weaving  defects  in  the  fabric  itself; 
and  for  careless  application  of  the  cement.  Special  tests  were  con- 
ducted for  flexibility,  as  a  stiff  hose  would  produce  a  strain  on  the 
soldier's  mouth;  for  permanent  set  to  insure  that  the  hose  was  properly 
cured;  for  the  adhesion  of  the  fabric  covering  to  the  hose;  and  for 
kinking  when  the  hose  was  doubled  on  the  fingers.  Finally  each  piece 
was  subjected  to  a  test  for  leaks  under  water  with  a  pressure  of 
5  lbs.  per  sq  in. 

"Each  eyepiece  and  the  three-way  metal  connection  to  the  facepieee 
were  subjected  to  a  vacuum  test  for  leakage.  The  delicate  exhalation 
valve  was  carefully  examined  for  defects  whiclT  would  be  liable  to 
cause  leakage.  Fabric  for  the  facepieee  was  given  a  high-tension 
electrical  test  on  a  special  machine  developed  at  the  plant  to  overcome 
the  difficulty  met  in  the  inspection  of  this  most  important  material. 
It  was  of  course  necessary  that  the  facepieee  fabric  be  free  from 
defects  but  just  what  constituted  a  defect  was  the  source  of  much 
discussion.  The  electrical  test  eliminated  all  personal  views  and  gave 
an  impartial  test  of  the  fabric.  The  machine  consisted  of  two  steel 
rolls  between  which  a  potential  difference  of  4,000  volts  was  main- 
tained; the  fabric  was  led  through  the  rolls  and  wherever  there  was 

V.  Ind.  Eng.  Chem.,  11,  185    (1919). 


DEVELOPMENT  OF  THE  GAS  MASK  221 

a   pinhole   or  flaw   the   current   arced   through  and  burned   a   clearly 
visible  hole. 

"Preliminary  Facepiece  Operations — Blanks  were  died  out  from 
the  facepiece  fabric  in  hydraulic  presses.  Each  face  blank  was  swabbed 
to  remove  bloom  and  the  eye  washers  were  cemented  about  the  eyeholes. 
The  pockets  for  holding  the  noseclips  were  also  cemented  to  the  blanks. 
The  bands  which  formed  a  gas-tight  seal  of  the  mask  about  the  face 
were  died  out  from  rubberized  fabric  to  which  a  felt  backing  was 
attached.  The  harness  consisting  of  elastic  and  cotton  tapes  was  also 
sewed  together  at  this  point. 

"Facepiece  Operations — The  sewing  machine  operations  were  next 
performed.  First  the  died  out  blanks  were  pleated  to  form  the 
facepiece.  The  operator  had  to  register  the  various  notches  in  the 
blank  to  an  accuracy  of  y^  in.  and  to  locate  the  stitches  in  some  cases 
as  closely  as  '/«  in.  The  band  was  next  sewed  to  the  periphery  of  the 
facepiece  after  which  the  harness  was  attached.  The  stitches  on  the 
outside  of  the  facepiece  were  covered  with  liquid  dope,  which  filled 
the  needle  holes  and  made  the  seams  gas-tight. 

"In  addition  to  the  inspection  of  each  operation,  the  completed 
facepiece  was  submitted  to  a  control  inspection  to  discover  any  defects 
that  might  escape  the  attention  of  the  inspectors  on  the  various 
operations. 

"Assembly  Operations — The  facepieces  were  now  ready  for  assem- 
bly and  were  sent  for  insertion  of  the  eyepieces,  which  was  done 
in  specially  designed  automatic  presses.  The  eyepieces  had  to  be 
carefully  inserted  so  that  the  facepiece  fabric  extended  evenly  around 
the  entire  circumference. 

"Before  manufacture  began  on  a  large  scale,  the  most  satisfactory 
method  of  conducting  each  assembly  operation  was  worked  out  and 
the  details  standardized,  so  that  operators  could  be  quickly  and  effi- 
ciently trained.  No  detail  was  considered  too  small  if  it  improved  the 
quality  of  the  mask.     The  assembly  operations  proceeded  as  follows: 

"The  exhalation  valve  was  first  joined  to  the  three-way  metal  tube 
which  formed  the  connection  between  the  facepiece,  flexible  hose,  and 
mouthpiece.  Each  valve  was  then  tested  for  leakage  under  a  pressure 
difference  of  a  one-inch  head  of  water.  No  valve  was  accepted  which 
showed  leakage  in  excess  of  10  cc.  per  min.  under  these  conditions. 

"The  metal  guard  to  protect  the  exhalation  valve  was  next  assembled, 
followed  by  the  flexible  hose.  The  three-way  tube  was  then  assembled 
to  the  facepiece  by  means  of  a  threaded  connection  and  the  rubber 
mouthpiece  attached.  To  illustrate  the  attention  to  details  the  follow- 
ing operation  may  be  cited: 


222  CHEMICAL   WARFARE 

"The  contact  surfaces  between  each  rubber  and  metal  part  were 
coated  with  rubber  cement  before  the  parts  were  assembled.  The 
connection  was  then  tightly  wired,  care  being  taken  that  none  of  the 
turns  of  wire  should  cross  and  finally  the  wire  was  covered  with  adhesive 
tape  so  that  no  sharp  edges  would  be  exposed. 

"The  masks,  completely  assembled  except  for  the  canisters,  were 
inspected  and  hung  on  racks  on  specially  des'gned  trucks  which  pre- 
vented injury  in  transit,  and  were  delivered  to  the  Finishing  Depart- 
ment. 

"Canister  Filling — Meanwhile  the  canisters  were  being  filled,  in 
another  building. 

"The  chemicals  were  first  screened  in  such  a  way  that  the  fine 
and  coarse  materials  were  separated  from  the  correctly  sized  materials. 
They  were  then  carried  on  a  belt  conveyor  to  the  storage  bins,  whence 
they  were  fed  by  gravity  through  pipes  to  various  mixing  machines. 
A  special  mixing  machine  was  developed  to  mix  the  carbon  and  granules 
in  the  proper  proportions  for  use  in  the  canister.  The  mixed  chemicals 
were  then  led  to  the  canister-filling  machines.  There  was  a  separate 
mixing  machine  for  each  filling  machine,  of  which  there  were  eighteen 
in  all. 

"The  can-filling  department  was  laid  out  in  six  units.  Each  unit 
had  a  capacity  of  20.000  cans  per  day.  A  system  of  double  belt  con- 
veyors was  installed  to  conduct  empty  canisters  to  the  machines  and 
carry  away  the  filled  ones. 

"Each  filling  operation  was  carefully  inspected  and  special  stops 
were  placed  on  the  belt  conveyors  so  that  a  canister  could  not  go  to 
the  next  operation  without  having  been  inspected.  Operators  and 
inspectors  were  stationed  on  opposite  s'des  of  the  belt.  The  chemicals 
were  placed  in  the  canister  in  three  equal  layers  which  were  separated 
by  pads  of  cotton  wadding.  The  first  layer  was  introduced  from  the 
filling  machine  (which  delivered  automatically  the  proper  volume  of 
chemicals),  the  canister  was  shaken  to  pack  the  chemicals  tightly, 
the  cotton  baffle  inserted,  the  second  layer  of  chemicals  introduced  and 
so  forth.  On  top  of  the  top  layer  of  chemicals  were  placed  a  wire 
screen  and  a  specially  designed  spring  which  held  the  contents  of  the 
canister  securely  in  place.  The  metal  top  was  then  fitted  and  securely 
soldered. 

"Each  canister  was  tested  under  water  for  possible  leaks'  in  joints 
or  soldering,  with  an  air  pressure  of  5  lbs.  per  sq.  in.  A  test  was 
also  made  for  the  resistance  which  it  offered  to  breathing,  a  rate  of 
flow  of  air  through  the  canister  of  85  liters  per  min.  being  maintained 
and  the  resistance  being  measured  in  inches  of  wafor. 


DEVELOPMENT  OF  THE  GAS  MASK 


223 


"The  filled  canisters  were  then  painted  a  distinctive  color  to  indicate 
the  type  of  filling. 

"Finishing  Department — In  the  finishing  department,  the  filled 
canisters,  were  conducted  down  the  middle  of  the  finishing  tables  and 
assembled  to  masks. 


THE  ULTIMATE 


\^hy  Not  Nou)  f 


Fig.  59. 


m 


"The  finished  masks  were  then  inspected,  placed  in  unit  boxes, 
ten  to  a  box,  and  returned  for  the  final  inspection. 

"Final  Inspection — Final  inspection  of  the  completely  assembled 
masks  was'  as  rigid  as  could  be  devised,  and  was  closely  supervised 
by  army  representatives.  Only  the  most  painstaking,  and  careful 
women  were  selected  for  this  work  and  the  masks  were  examined  in 
very  detail  to  discover  any  defect  that  might  have  escaped  previous 


224  CHEMICAL  WARFARE 

inspection.  Finally,  each  mask  was  inspected  over  a  bright  light  in 
a  dark  booth  for  small  pinholes  which  the  ordinary  visual  inspection 
might  not  have  detected.  U 

"As  a  check  on  the  quality  on  the  final  inspectors'  work  a  rein-  ^ 
spection  of  5  per  cent  of  the  passed  masks  was  conducted.  Where 
it  was  found  that  a  particular  inspector  was  making  numerous  mistakes, 
her  eyes  were  examined  to  see  whether  it  was  due  to  faulty  eyesight 
or  careless  work.  Masks  containing  known  defects  were  purposely 
sent  to  these  inspectors  to  determine  whether  they  were  capable  of 
continuing  the  inspection  work.  In  this  way  the  desired  standard 
was  maintained. 

"A  daily  report  of  the  final  inspection  was  sent  back  to  each  of 
the  assembly  departments  involved  so  that  defects  might  be  eliminated 
immediately  and  the  percentage  of  rejects  kept  as  low  as  possible. 

"After  the  final  inspection  the  masks  were  numbered,  packed  in 
knapsacks,  and  the  filled  knapsacks  placed  in  packing  cases,  twenty- 
four  to  a  case." 


TissoT  Mask 

The  French,  as  has  already  been  pointed  out,  early  recognized 
that  certain  classes  of  fighting  men,  as  the  artillerymen,  needed 
the  maximum  of  protection  with  the  minimum  decrease  in 
efficiency.  The  result  of  this  was  the  Tissot  Mask.  Before  the 
United  States  entered  the  war,  the  British  standard  box  res- 
pirator had  reached  a  greater  degree  of  perfection,  with  far 
greater  ruggedness  and  portability.  It  was  therefore  adopted  as 
the  American  standard.  At  the  time  of  the  invention  of  the 
British  box  respirator  and  practically  up  to  the  time  the  United 
States  entered  the  war,  masks  were  worn  only  during  the 
sporadic  gas  attacks  then  occurring  and  only  for  a  brief  period 
at  a  time.  As  the  war  progressed,  the  men  were  compelled  to 
wear  their  masks  for  much  longer  periods  (eight  hours  was  not 
uncommon).  It  was  then  seen  that  more  comfort'  was  needed, 
even  at  the  expense  of  a  little  safety. 

The  principle  of  the  Tissot  mask  was  correct  so  far  as  comfort 
was  concerned,  since  it  did  away  with  the  irritating  mouthpiece 
and  noseclip,  but  the  chief  danger  in  the  French  mask  arose 
from  the  fact  that  the  facepiece  was  made  of  thin,  pure  gum 
rubber.     The  Research  Division,  together  with  the  Gas  Defense 


DEVELOPMENT  OF  THE  GAS  MASK 


225 


Division,  developed  two  distinct  types  of  Tissot  masjis.  The. 
first  of  these  was  the  Akron  Tissot,  the  second  the  Kops  Tissot. 
The  best  features  of  these  have  been  combined  in  the  1919 
Model. 


Fig.  60. — American  Tissot  Mask, 
Early  Type. 


Fig.  61. — American  Tissot 
Mask,  Interior  View. 


1919  Model  American  Mask 


Facepiece.  This  facepiece  is  made  of  rubberized  stockinet 
about  one-tenth  inch  in  thickness.  The  stockinet  is  on  the  out- 
side only  and  is  for  the  purpose  of  strengthening  and  protect- 
ing the  rubber  which  is  of  very  high  grade.  The  facepiece  is 
died  out  as  a  single  flat  piece  from  the  stockinet  which  is  fur- 
nished in  long  rolls.  The  die  is  of  such  shape  that  when  the 
facepiece  is  sewed  there  is  but  one  seam,  and  that  between 


226  CHEMICAL    WARFARE 

the  angle  tube  opening  and  the  edge  under  the  chin.  This  seam 
is  sewed  with  a  zigzag  stitch  with  the  stockinet  sides  flat 
together.  The  seam  is  then  stretched  over  a  jig,  so  as  to  form 
a  flat  butt  joint.  This  seam  is  then  cemented  with  rubber 
cement  and  taped,  inside  and  out,  to  make  it  thoroughly  gas- 
proof. 

The  eyepiece  openings  are  of  oval  shape  with  the  longer 
'axes  horizontal  and  considerably  smaller  than  the  finished  eye- 
pieces. The  eyepieces  being  circular,  the  cloth  is  stretched  to 
accommodate  them,  giving  the  necessary  bulge  to  keep  the  cloth 
and  metal  of  the  eyepieces  away  from  the  face.  The  harness 
has  three  straps  on  each  side.  Instead  of  the  single  strap  over 
the  top  of  the  head,  two  straps  lead  from  directly  over  the  eyes, 
both  being  made  of  elastic  the  same  as  the  other  straps.  All 
six  straps  are  brought  together  around  a  pad  of  felt  and  cloth 
about  21^X31/^  inches  at  the  back  of  the  head.  This  pad  makes 
(the  harness  much  more  comfortable. 

The  rubberized  stockinet  is  reinforced  on  the  inner  or  rub- 
'ber  side  with  thin  bits  of  cloth  at  all  points  where  the  straps 
are  sewed  on.    The  strap  across  the  temples  just  above  the  ears 
|is  sewed  at  two  points,  one  about  one-half  inch  from  the  edge 
I  and  the  other  about  two  inches  from  the  edge.    This  is  for  the 
ipurpose  of  helping  press  the  cloth  against  the  temples,  thereby 
I  adding  to  the  gas-tightness  for  those  heads  that  have  a  ten- 
dency to  be  hollow  at  the  temples.     The  lower  strap  is  just 
above  the  chin  and  is  for  the  purpose  of  giving  gas-tightness  in 
that  vicinity.     All  of  the  straps  except  the  two  over  the  top 
of  the  head  are  attached  to  the  pad  with  buckles,  and  are  thus 
capable  of  exact  adjustment. 

The  eyepieces  are  of  triplex  glass  in  metal  rings  with  rubber 
gaskets.  In  pressing  the  rings  home,  the  rubberized  stockinet 
is  turned  and  held  securely  so  that  there  is  no  possibility  of 
pulling  them  out.  The  angle  tube  containing  the  outlet  valve 
and  the  connection  to  the  corrugated  tube  connecting  with  the 
canister  is  the  same  as  with  the  latest  model  R.  F.  K.  mask. 
The  only  difference  as  regards  the  corrugated  tube  is  that  a 
greater  length  is  needed  with  the  new  carrier  under  the  left 
shoulder.  The  total  length  of  the  tube  for  this  model  is  about 
24  inches.     On  the  inside  of  the  facepiece  and  connected  to 


DEVELOPMENT  OF  THE  GAS  MASK 


227 


the  angle  tube  inlet  is  a  butterfly  baffle  of  rubber,  so  arranged 
that  the  incoming  air  is  thrown  upward  and  over  the  eyepieces, 


Fig.  62. — 1919  Model  American  Mask. 


thus  keeping  them  clear  no  matter  how  much  the  exertion  or 
what  the  temperature,  except  in  certain  rare  cases  when  the 
temperature  is  down  at  zero  F.  or  below. 


228  CHEMICAL  WARFARE 


Canister 


The  canister  is  radically  different  from  the  canisters  used 
in  the  R.  F.  K.  and  earlier  types.  In  the  first  place,  it  is  longer, 
the  total  length  finished  being  8  inches.  It  has  two  inlet  valves 
at  the  top  end  protected  by  a  tin  cover  instead  of  the  single 
inlet  valve  at  the  bottom  of  the  earlier  types.  The  two  inlet 
valves  are  each  %  inch  in  diameter  and  are  made  up  of  square 
flat  valves  on  the  end  of  a  short  rubber  tube.  The  rubber  tube 
is  fitted  over  a  short  metal  tube.  Gas-tightness  is  obtained 
both  by  the  pressing  of  the  valve  against  the  round  edge  of  the 
metal  tube  and  by  the  pressure  of  the  edges  against  each  other. 
These  valves,  while  delicate,  are  proving  very  satisfactory,  and 
being  simply  check  valves  to  prevent  the  air  going  back 
through  the  canister,  they  are  not  vital.  In  case  of  failure,  the 
eyepieces  would  fog  somewhat  and  the  dead  air  space  be  in- 
creased by  that  held  in  the  inlet  tube. 

The  canister  consists  really  of  two  parts — an  outer  casing 
that  is  solid  and  an  inner  perforated  tin  casing.  Around  the 
perforated  tin  is  fitted  a  filter  of  wool  felt  Vie  of  an  inch  in 
thickness.  This  wool  felt  is  very  securely  fastened  by  turning 
operations  to  solid  pieces  of  tin,  top  and  bottom,  so  that  no  air 
can  get  into  the  chemicals  without  passing  through  the  filter. 
Thus  the  air  coming  through  the  inlet  valves  at  the  top  circu- 
lates around  the  loosely  fitting  outside  corrugated  case  to  all 
parts  of  the  filter  and  after  passing  through  the  filter  continues 
through  the  perforations  of  the  tin  into  the  charcoal  and  soda- 
lime  granules. 

The  chemicals  are  packed  around  a  central  wedge-shaped 
tube  extending  about  two-thirds  the  length  of  the  can.  The 
wedge  is  enlarged  at  the  top  and  made  circular  where  it  passes 
through  the  top  of  the  can  to  connect  with  the  corrugated  tube. 
The  wedge-shaped  inner  piece  is  made  of  perforated  tin  and 
is  covered  with  thin  cloth  to  prevent  dust  from  the  chemicals 
passing  into  the  tube  and  thus  into  the  lungs.  The  cans  are 
filled  from  the  bottom  and  are  subjected  to  two  mechanical 
jarring  operations  in  order  to  settle  the  chemicals  thoroughly 
before  the  spring  which  holds  them  in  place  is  added.     The 


DEVELOPMENT  OF  THE  GAS  MASK 


229 


outer  tin  cap  protecting  the  inlet  valves  has  two  openings  on 
each  side  but  none  at  the  ends  of  the  canister. 

The  carrier  is  a  simple  canvas  case  nearly  rectangular,  about 
one  foot  wide  and  15  inches  in  length.    The  width  is  just  suf- 


t 


Fig.  63 — 1919  Model  American  Mask  after  Adjustment. 


ficient  at  the  back  to  hold  the  canister  and  the  front  part  to 
hold  the  extra  length  of  corrugated  tube  and  the  facepiece. 
There  are  two  straps,  one  passing  over  the  right  shoulder  and 
the  other  around  the  body.     The  one  passing  over  the  right 


230  CHEMICAL   WARFARE 

shoulder  has  two  **V"  shaped  seams  at  the  top  so  as  to  change 
the  direction  of  the  strap  over  the  shoulder  in  order  that  it 
will  pull  directly  downward  instead  of  against  the  neck.  The 
flap  closing  the  case  opens  outward. 

It  has  the  usual  automobile  curtain  fasteners.  A  secondary 
fastener  at  the  top  of  the  opening  is  arranged  so  that  when  liio 
tube  is  adjusted  to  the  proper  length  and  the  mask  is  adjusted 
to  the  face  of  the  wearer,  the  flap  can  be  buttoned  tightly  over 
the  corrugated  tube  and  held  tightly.  This  prevents  water 
from  entering  the  case. 

Figures  62  and  63  show  the  position  of  the  carrier  both  with 
the  facepiece  in  the  carrier  and  after  adjustment.  It  will  be 
noted  that  the  carrier  does  not  interfere  with  the  pack  nor  with 
anything  on  the  front  of  the  body.  The  left  arm  hangs  almost 
entirely  natural  over  the  case.  It  has  been  thoroughly  tried 
out  by  the  Infantry,  Cavalry,  Artillery  and  Special  Gas  Troops 
and  adopted  as  eminently  satisfactory. 

Special  Canisters 

Navy.  The  early  Navy  canister  is  a  drum  much  like  the 
German  canister.  The  container  is  ^  slightly  tapered  metal 
cylinder,  9  cm.  in  diameter  at  the  bottom.  The  most  satis- 
factory fllling  for  this  drum  consists  of  tWo  layers,  98  cc.  in 
each,  of  a  standard  mixture  of  charcoal  and  soda  lime, 
separated  by  cotton  wadding  pad.  The  filling  is  6-20  mesh, 
instead  of  8-14  mesh.    A  later  type  is  shown  in  Figure  41. 

Carbon  Monoxide.   This  canister  is  discussed  in  Chapter  XI. 

Ammonia.  Ammonia  respirators  were  needed  by  the  Navy 
and  also  by  the  workmen  in  refrigeration  plants.  Early  pro- 
tection was  obtained  by  the  use  of  pumice  stone  impregnated 
with  sulfuric  acid.  This  had  many  disadvantages,  such  as  the 
amount  of  heat  evolved,  the  caustic  fumes  produced,  high 
resistance  and  corrosion  of  the  canister.  To  overcome  these, 
the  ''Kupramite"  canister  was  developed.  The  filling  consists 
of  pumice  stone  impregnated  with  copper  sulfate.  Pumice 
stone,  8  to  14  mesh,  and  technical  copper  sulfate  are  placed 
in  an  evaporating  pan  in  the  ratio  of  one  part  by  weight 
CUSO4  •  5II2O  to  1.5  parts  pumice,  and  the  whole  is  covered 


DEVELOPMENT  OF   THE  GAS  MASK 


231 


vvith  sufficient  water  to  dissolve  the  salt  at  boiling  temperature. 
The  mixture  is  then  boiled  down  with  constant  stirring  until 
crystallization  takes  place  on  the  pumice  and  the  crystals  are 
nearly  dry.  The  pumice  thus  treated  is  then  removed  from  the 
dish,  spread  out  and  allowed  to  dry  in  the  air.  The  fines  are 
then  screened  out  on  a  14-mesh  sieve.  Care  must  be  taken 
in  the  evaporating  process  that  the  absorbent  is  still  slightly 
moist  when  taken  from  the  pan. 


FiGr64. — Early  Type  Navy  Mask.    Contains  nose  clip  and  mouthpiece. 

In  packing  the  standard  Army  canister  with  kupramite  a 
layer  of  toweling  is  placed  on  top  of  the  absorbent  to  filter  out 
any  fine  particles  which  might  be  drawn  up  from  the  absorbent, 
and  the  whole  is  held  in  place  by  the  usual  heavy  wire 
screen  and  spring.  This  method  of  packing  is  to  be  used 
with  the  present  mouthpiece  type  of  army  mask.  If  the  new 
Tissot  type  mask  is  used,  a  modification  of  the  packing 
is  desirable  in  order  to  eliminate  the  trouble  due  to  moisiure 
given  off  by  the  absorbent  during  service  condensing  on  the 
eyepieces  of  the  mask  and  thus  impairing  the  vision  of  the 
wearer.    To  remedy  this  defect  a  1-in.  layer  of  kupramite  at 


232 


CHEMICAL  WARFARE 


the  top  of  the  canister  is  replaced  by  activated  charcoal  or 
silica  gel,  preferably  silica  gel.  This  decreases  the  humidity 
of  the  effluent  air  sufficiently  to  prevent  dimming  of  the  eye- 
pieces. If  charcoal  is  used,  a  2-8  cotton  pad  (Eastern  Star 
Furrier  Co.,  Pawtucket,  R.  I.)  is  substituted  for  the  toweling 
in  order  to  remove  charcoal  dust.  The  canister  complete 
weighs  about  1.7  lbs. 

A  canister  containing  45  cu.  in.  of  this  material  will  protect 
a  man  breathing  at  rest  for  at  least  5  hours  against  2  per  cent 


-Valve 


Fig.  65. — Ammonia  Canister — "Kupramite." 

ammonia  and  for  21^  hours  against  5  per  cent  ammonia.  Its 
advantages  are  large  capacity  and  activity,  negligible  heat  of 
absorption,  and  cheapness. 


Physiological  Features  of  the  Mask 

For  some  time  after  the  introduction  of  gas  warfare,  the 
gases  used  were  of  the  so-called  non-persistent  type.  Under 
these  conditions  it  was  necessary  to  wear  the  mask  for  only 
relatively  short  periods,  after  which  the  cloud  dissipated.  With 


DEVELOPMENT  OF  THE  GAS  MASK 


233 


the  increasing  use  of  gas  and  the  introduction  of  the  more 
persistent  gases,  particularly  mustard  gas,  it  not  only  became 
necessary  to  wear  the  mask  for  long  periods  of  time  but  also  to 
do  relatively  heavy  physical  work,  such  as  serving  artillery, 
when  wearing  the  mask. 

Under  these  conditions,  it  became  evident  that  the  wear- 
ing of  the  mask  caused  a  very  great  reduction  in  the  military 
efficiency  of  the  soldier.     The  reasons  for  this  reduction  in 


Fig.  66. — Ammonia  Mask,  Showing  Relative  Size  of  Canister. 


efficiency  have  been  made  the  subject  of  extensive  research  by  a 
group  of  the  foremost  physiologists  and  psychologists  of  the 
country.  As  a  result  of  their  work,  the  causes  contributing  to 
this  reduction  in  efficiency  may  be  grouped  about  the  following 
main  factors: 

(1)  The  physical  discomfort  of  the  mask  arising  from  causes 
such  as  pressure  on  the  head  and  face,  due  to  improperly  fitting 
facepieces  and  harness,  the  noseclip,  and  the  mouthpiece. 


234  CHEMICAL  WARFARE 

(2)  Abnormal  conditions  of  vision,  due  to  poor  optical  quali- 
ties in  eye  pieces  and  restrictions  of  vision,  both  as  to  total  field 
and  binocular  field. 

(3)  Abnormal  conditions  of  respiration,  among  them  being 
(a)  the  unnatural  channels  of  respiration  caused  by  wearing  the 
box  respirator,  (b)  increase  in  dead  air  space  in  respiratory 
circuit,  and  (c)  the  increase  in  resistance  to  both  inhalation  and 
exhalation,  the  last  two  mentioned  being  present  to  a  greater  or 
less  degree  in  all  types  of  mask. 

Of  these  general  subdivisions  the  various  phases  of  the  first 
two  are  so  evident  that  no  further  discussion  will  be  given.  The 
effects  of  the  changed  conditions  of  respiration  are,  however,  less 
obvious,  and  it  may  be  of  interest  to  present  in  a  general  way  the 
results  of  the  research  along  this  line,  particularly  as  regards  the 
harmful  effects  of  increasing  the  resistance  and  dead  air  space  in 
the  respiratory  tract  above  the  normal. 

The  function  of  respiration  is  to  supply  oxygen  to  and  remove 
carbon  dioxide  'from  the  blood  as  it  passes  through  the  lungs. 
This  interchange  of  gases  takes  place  in  the  alveoli,  a  myriad  of 
thin-walled  air  sacs  at  the  end  of  the  respiratory  tract  where 
the  air  is  separated  by  a  very  thin  membrane  through  which  the 
gases  readily  pass.  The  volume  and  rate,  or  in  other  words,  the 
minute-volume,  of  respiration  is  automatically  controlled  by  the 
nerve  centers  in  such  a  way  that  a  sufficient  amount  of  air  is 
supplied  to  the  lungs  to  maintain  by  means  of  this  interchange  a 
uniform  percentage  of  its  various  constituents  as  it  leaves  the 
lungs.  It  will  be  readily  seen  therefore,  that  anything  which 
causes  a  change  in  the  composition  of  the  air  presented  to  the 
blood  in  the  alveoli  will  bring  about  abnormal  conditions  of 
respiration. 

Inasmuch  as  the  gaseous  interchange  between  the  lungs  and 
the  blood  takes  place  only  in  the  terminal  air  sacs  it  follows 
that,  at  the  end  of  each  respiration,  the  rest  of  the  respiratory 
tract  is  filled  with  air  low  in  oxygen  and  high  in  carbon  dioxide, 
which  on  inspiration  is  drawn  back  into  the  lungs,  diluting  the 
fresh  air.  The  volume  of  these  passages  holding  air  which  must 
be  re-breathed  is  known  as  the  anatomical  dead  air  space. 

Similarly,  when  a  mask  is  worn  the  facepiece  chamber  and 
any  other  parts  of  the  air  passage  common  to  inspiration  and 


DEVELOPMENT  OF   THE  GAS  MASK  235 

expiration  become  additional  dead  air  space  contributing  a 
further  dilution  of  oxygen  content  and  contamination  by  carbon 
dioxide  of  the  inspired  air  in  addition  to  that  occasioned  by  the 
anatomical  dead  space,  which  of  course,  is  always  present  and  is 
taken  care  of  by  the  functions  normally  controlling  respiration. 
Major  R.  G.  Pearce  who  directed  a  large  amount  of  the 
research  along  this  line,  sums  up  the  harmful  effects  of  thus  in- 
creasing the  dead  air  space  as  follows : 

1.  Interpretation  from  the  physiological  standpoint: 
(a)  A  larger  minute-volume  of  air  is  required  when  breath- 
ing through  dead  air  space.  This,  interpreted  on  physiological 
grounds,  means  that  the  carbon  dioxide  content  of  the  arterial 
blood  is  higher  than  normal.  The  level  to  which  the  content  of 
carbon  dioxide  in  the  arterial  blood  may  rise  is  limited.  Any- 
thing which  wastefully  increases  the  carbon  dioxide  level  of  the 
blood  decreases  the  reserve  so  necessary  to  a  soldier  when  he  is 
asked  to  respond  to  the  demand  for  exercise  which  is  a  part  of 
his  daily  life. 

(6)  A  larger  minute-volume  of  air  must  be  pulled  through 
the  canister,  which  offers  resistance  proportional  to  the  volume 
of  air  passing  through  it.  If  resistance  is  a  factor  of  harm,  dead 
air  space  increases  that  harm,  since  dead  air  space  increases  the 
volume  of  air  passing  through  the  canister. 

(c)  As  will  be  noted  below,  the  effect  of  resistance  is  a  ten- 
dency to  decrease  the  minute-volume  of  air  breathed.  Dead  air 
space  increases  the  minute-volume.  Accordingly,  if  breathing  is 
accomplished  against  resistance  and  through  a  large  volume  of 
dead  air  space,  the  volume  of  air  breathed  is  reduced  more  in 
proportion  to  the  actual  needs  of  the  body  than  when  breathing 
against  resistance  without  the  additional  factor  of  dead  space; 
this,  again,  causes  the  level  of  carbon  dioxide  in  the  blood  and 
issues  to  be  raised  to  a  higher  level  than  normal,  and  thus  again 
ere  is  some  reserve  power  wasted. 

2.  Interpretation  from  the  standpoint  of  the  canister. 

tThe  life  of  the  canister  depends  on  the  volume  of  the  gas- 
den  air  passed  through  it.  The  dead  space  increases  the 
inute-volume  of  air  passed  through  the  canister  and,  therefore, 


^_tis! 


236  CHEMICAL   WARFARE 

Physiologically,  the  reason  for  the  harmful  effects  of  breath- 
ing resistance  is  more  involved : 

"The  importance  of  resistance  to  breathing  lies  in :  (1)  the  effect 
on  the  circulation  of  the  blood,  and  (2)  the  changes  in  the  lung  tissue, 
which  seriously  interfere  with  the  gas  exchange  between  the  outside 
air  and  the  blood.  Data  have  been  presented  to  draw  attention  to 
the  seriousness  of  resistance  to  inspiration.  In  these  reports,  it  was 
suggested  that  the  deleterious  effects  on  the  body  consist  in  changes 
in  the  blood  pressure,  increased  work  of  the  right  side  of  the  heart, 
and  an  increase  in  the  blood  and  lymph  content  of  the  lungs.  Resistance 
also  decreases  the  minute-volume  of  air  breathed  and  thereby  increases 
the  percentage  of  carbon  dioxide  in  the  expired  air.  The  foregoing 
changes  are  all  deleterious. 

"Although  the  chief  problem  of  resistance  in  gas  mask  design 
concerns  inspiration,  nevertheless  resistance  to  expiration  is  an  im- 
portant factor.  The  expired  air  of  the  lungs  contains  carbon  dioxide 
for  which  means  of  escape  must  be  provided.  The  expiratory  act 
is  more  passive  than  the  inspiratory  act,  and  resistance  to  expiration 
is,  therefore,  more  keenly  felt  than  resistance  to  inspiration.  It  is 
then  imperative  that  the  exhale  valve  be  so  arranged  as  to  allow  for 
the  escape  of  the  entire  amount  of  air  during  the  time  of  expiration 
with  the  least  possible  resistance.  The  data  of  the  laboratory  indicate 
that  seldom,  if  ever,  do  expiratory  rates  rise  above  a  velocity  of  150 
to  175  per  minute.  The  effect  of  resistance  to  exhalation  upon  the 
vital  organs  of  the  body  is  not  dissimilar  to  that  of  inspiration." 


CHAPTER  XIII 
ABSORBENTS^ 

The  absorbents  used  in  both  the  British  and  American  gas 
mask  canister,  which  afforded  a  degree  of  protection  far  superior 
to  that  of  any  other  allied  or  enemy  nation  except  Germany, 
consisted  of  a  mixture  of  charcoal  and  soda  lime,  as  described  in 
the  preceding  chapter..  In  general,  a  gas  mask  absorbent  must 
have  certain  requirements.  These  are:  absorptive  activity, 
absorptive  capacity,  versatility,  mechanical  strength,  chemical 
stability,  low  breathing  resistance,  ease  of  manufacture  and 
availability  of  raw  materials. 

Absorptive  activity,  or  a  very  high  rate  of  absorption,  is  one 
of  the  more  important  properties  of  a  satisfactory  absorbent.  A 
normal  man  when  exercising  violently  breathes  about  60  liters 
of  air  per  minute,  and  since  inhalation  occupies  but  slightly  more 
than  half  of  the  breathing  cycle,  the  actual  rate  at  which  gas 
passes  through  the  canister  during  inhalation  is  about  100  liters 
per  minute.  Calculated  on  the  basis  of  the  regular  army  canis- 
ter, this  corresponds  to  an  average  linear  air  velocity  of  about 
80  cm.  per  second.  On  the  average,  therefore,  a  given  small 
portion  of  the  air  remains  in  contact  with  the  gas  absorbent  for 
only  about  0.1  second.  Besides  this,  the  removal  of  the  toxic 
material  must  be  surprisingly  complete.  Though  the  concen- 
tration entering  the  canister  may  occasionally  be  as  high  as  one 
half  per  cent,  even  the  momentary  leakage  of  0.001  per  cent  (ten 
parts  per  million)  would  cause  serious  discomfort  and  the  pro- 
longed leakage  of  smaller  amounts  would  have  serious  results  in 
the  case  of  some  gasas.  The  activity  of  the  present  gas  mask 
charcoal  is  shown  by  the  fact  that  it  will  reduce  a  concentration 

*  The  basis  of  this  chapter  is  the  series  of  articles  by  Lamb  and 
co-workers  which  appeared  in  the  J.  Ind.  Eng.  Chem.  for  1919. 

237 


238  CHEMICAL  WARFARE 

of  7000  parts  per  million  of  chloropicrin  to  less  than  0.5  part 
per  million  in  less  than  0.03  second. 

Of  equal  importance  is  the  absorptive  capacity.  That  is,  the 
absorbent  must  be  able  to  absorb  and  hold  large  amounts  of  gas 
per  unit  weight  of  absorbent.  Its  life  must  be  measured  in  days 
against  ordinary  concentrations  of  gas.  It  is  further  necessary 
that  the  gas  be  held  firmly  and  not  in  any  loose  combination 
which  might  give  up  minute  traces  of  gas  when  air  is,  for  long 
periods  of  time,  breathed  in  through  a  canister  which  has  pre- 
viously been  exposed  to  gas. 

The  absorbents  used  must  be  of  a  type  which  can  be  relied 
upon  to  give  adequate  protection  against  practically  any  kind  of 
toxic  gas  (versatility).  The  need  of  this  is  apparent  when  the 
difificulty  of  having  separate  canisters  for  various  gases  is  con- 
sidered, as  well  as  the  difficulty  in  rapidly  and  accurately  identi- 
fying the  gases  and  the  possible  introduction  of  new  and 
unknown  gases.  Fortunately,  practically  all  of  the  toxic  gases 
are  very  reactive  chemically  or  have  relatively  high  boiling 
points  and  can  therefore  be  absorbed  in  large  amounts  by  char- 
coal. 

Absorbents  must  be  mechanically  strong  in  order  to  retain 
their  structure  and  porosity  under  conditions  of  transport  and 
field  use.  Further,  they  must  not  be  subject  to  abrasion  for  the 
production  of  a  relatively  small  amount  of  fines  would  tend  to 
plug  the  canister  or  to  cause  channels  through  which  the  gas 
would  pass  without  being  absorbed. 

Since  the  canister  is  filled  several  months  before  it  is  first 
used  in  the  trenches,  and  since  the  canister  may  be  used  over  a 
period  of  months  before  it  is  discarded,  it  is  obviously  the  ulti- 
mate activity  and  capacity  (not  the  initial  efficiency)  which 
determines  the  value  of  an  absorbent.  It  must  therefore  have  a 
very  considerable  degree  of  chemical  stability.  By  this  is  meant 
that  the  absorbent  itself  is  not  subject  to  chemical  deterioration, 
that  it  does  not  react  with  carbon  dioxide,  that  it  does  not  dis- 
integrate or  become  deliquescent  even  after  being  used  and  that 
it  has  no  corrosive  action  on  the  metal  container. 

In  a  good  general  absorbent  there  must  be  a  proper  balance 
between  its  various  essential  qualities,  and  hence  the  most 
suitable  mixture  will  probably  always  be  a  compromise. 


ABSORBENTS  239 

Charcoal 

The  fact  that  charcoal  would  condense  in  its  pores  or  adsorb 
certain  gases,  holding  them  firmly,  had  been  known  for  a  long 
time.^  In  general,  it  was  known  that  so-called  animal  charcoal 
was  the  best  for  decolorizing  sugar  solutions,  that  wood  charcoal 
was  the  best  for  adsorbing  gases  and  that  coke  had  very  little 
adsorbing  or  decolorizing  power.  No  one  knew  the  reason  for 
these  facts  and  no  one  could  write  a  specification  for  charcoal. 
The  ordinary  charcoal  used  in  the  scientific  laboratory  was 
cocoanut  charcoal,  since  Hunter  had  discovered  more  than  fifty 
years  ago  that  this  was  the  best  charcoal  for  adsorbing  gases. 

f    Raw  Materials^ 

The  first  charcoal  designed  to  offer  protection  against  chlorine 
and  phosgene  was  made  by  carbonizing  red  cedar.  Since  this 
had  little  value  against  chloropicrin,  attention  was  turned  to 
cocoanut  shell  as  the  source  of  raw  material.  This  charcoal  ful- 
filled the  above  conditions  for  a  satisfactory  absorbent  better 
than  any  other  form  tested.  It  must  not  be  supposed,  however, 
that  investigation  of  carbon  stopped  with  these  experiments. 
In  the  search  for  the  ideal  carbon,  practically  almost  every  hard 
vegetable  substance  known  was  tested.  Next  to  cocoanut  shells, 
the  fruit  pits,  several  common  varieties  of  nuts  abundant  in  the 
United  States,  and  several  tropical  nuts  (especially  cohune 
nuts),  were  found  to  make  the  best  carbon.  Pecan  nuts,  and  all 
woods  ranging  in  hardness  from  iron  wood  down  to  ordinary 
pine  and  fir,  were  found  to  be  in  the  second  class  of  efficiency. 
Among  other  substances  tested  were  almonds,  Arabian  acorns, 
grape  seeds,  Brazil  nut  husks,  balsa,  osage  orange,  Chinese  velvet 
bean,  synthetic  carbons  (from  coal,  lamp  black,  etc.),  cocoa  bean 
shell,  coffee  grounds,  flint  corn,  corn  cobs,  cotton  seed  husks, 
peanut  shells  and  oil  shale.  While  many  of  these  substances 
might  have  been  used  in  an  emergency,  none  of  them  would  pro- 
duce carbon  as  efficient,  volume  for  volume,  as  that  of  the  cocoa- 
nut  shell  and  other  hard  nuts. 

*  Bancroft  (J.  Phys.  Chem.  24,  127,  201,  342  (1920))  gives  a  compre- 
hensive review  of  *  *  Charcoal  before  the  War. ' ' 

^Part  of  this  section  is  quoted  from  '^Armies  of  Industry,"  by  Crowell 
an^  Wilson,  Yale  Univ.  Press. 


240  CHEMICAL  WARFARE 

Some  idea  of  the  scale  of  charcoal  production  may  be  seen 
from  the  requirement  for  cocoanut  shells.  When  we  first  began 
to  build  masks  our  demands  for  carboniferous  materials  ranged 
from  40  to  50  tons  a  day  of  raw  material ;  by  the  end  of  the  war, 
we  were  in  need  of  a  supply  of  400  tons  of  cocoanut  shells  per 
day.  This  demand  would  absorb  the  entire  cocoanut  production 
of  tropical  America  five  times  over.  (The  total  production  of 
cocoanuts  in  Central  America,  the  West  Indies  and  the  Caribbean 
Coast  of  South  America  amounted  to  131,000,000  nuts  annually, 
equal  to  a  supply  of  75  tons  of  shells  daily.)  It  was  equal  to 
one-tenth  of  the  total  production  of  the  Orient,  which  amounted 
to  7,450,200,000  nuts  annually.  This  large  demand  always  made 
a  reserve  supply  of  charcoal  material  practically  impossible. 
The  **Eat  More  Cocoanut"  campaign  started  by  the  Gas  Defense 
more  than  doubled  the  American  consumption  of  cocoanut  in  a 
brief  space  of  time  and  in  October,  1918,  with  the  help  of  im- 
portation of  shell,  we  averaged  about  150  tons  of  shells  per  day, 
exclusive  of  the  Orient. 

The  first  heating  of  cocoanut  shells  to  make  charcoal  reduces 
their  weight  75  per  cent.  It  was  evident,  therefore,  that  we 
could  more  economically  ship  our  oriental  supply  in  the  form  of 
charcoal  produced  on  the  other  side  of  the  Pacific  Ocean.  A 
charcoal  plant  was  established  in  the  Philippine  Islands  and 
agents  were  sent  to  all  parts  of  the  Oriental  countries  to  purchase 
enormous  supplies  of  shells.  While  the  work  was  only  gaining 
momentum  when  the  Armistice  was  signed,  the  plant  actually 
shipped  300  tons  of  cocoanut  shell  carbon  to  the  United  States 
and  had  over  1000  tons  on  hand  November  11,  1918. 

In  the  search  for  other  tropical  nuts,  it  was  found  that  the 
cohune  or  corozo  nut  was  the  best.  These  nuts  are  the  fruit  of 
the  manaca  palm  tree.  They  grow  in  clusters,  like  bananas  or 
dates,  one  to  four  clusters  to  a  tree,  each  cluster  yielding  from  60 
to  75  pounds  of  nuts.  They  grow  principally  on  the  west  coast 
of  Central  America  in  low,  swampy  regions  from  Mexico  to 
Panama  but  are  also  found  along  the  Caribbean  coast.  The  chief 
virtue  of  the  cohune  nut  from  the  charcoal  point  of  view  was  its 
extreme  thickness  of  shell ;  this  nut  is  3  inches  or  more  in  length 
and  nearly  2  inches  in  diameter  but  the  kernel  is  very  small. 
Four    thousand    tons    per    month    were    being    imported    at 


ABSORBENTS  241 

the  time  of  the  Armistice.  A  disadvantage  in  the  use  of  cohune 
nuts  was  that  their  husks  contained  a  considerable  amount  of 
acid  which  rotted  the  jute  bags  and  also  caused  the  heaps  of 
nuts  to  heat  in  storage. 

A  third  source  of  tropical  material  was  in  the  ivory  nuts 
used  in  considerable  quantities  in  this  country  by  the  makers  of 
buttons.  There  is  a  waste  of  400-500  tons  per  month  of  this 
material,  which  was  used  after  screening  out  the  dust.  This 
material  is  rather  expensive,  because  it  is  normally  used  in  the 
manufacture  of  lactic  acid. 

Another  great  branch  of  activity  in  securing  carbon  supplies 
was  concerned  with  the  apricot,  peach  and  cherry  pits  and 
walnut  shells  of  the  Pacific  Coast.  A  nation-wide  campaign  on 
the  part  of  the  American  Red  Cross  was  started  on  September 
13,  1918.  Between  this  time  and  the  Armistice  some  4,000  tons 
of  material  were  collected.  Thus  the  slogan  ''Help  us  to  give 
him  the  best  gas  mask"  made  its  appeal  to  every  person  in  the 
United  States. 

I        A  Theory  of  Charcoal  Action 

It  has  been  pointed  out  that  the  first  charcoal  was  made  from 
red  cedar.  While  this  was  very  satisfactory  when  tested  against 
chlorine,  it  was  of  no  value  against  chloropicrin.  In  order  to 
improve  the  charcoal  still  further  it  was  desirable  to  have  some 
theory  as  to  the  way  charcoal  acted.  It  was  generally  agreed 
that  fine  pores  were  essential.  The  functioning  of  charcoal 
depends  upon  its  adsorptive  power  and  this  in  turn  upon  its 
porosity.  The  greater  the  ratio  of  its  surface  to  its  mass,  that 
is,  the  more  highly  developed  and  fine  grained  its  porosity,  the 
greater  its  value.  Another  factor,  however,  seemed  to  play  a 
role.  As  a  pure  hypothesis,  at  first,  Chancy  assumed  that  an 
active  charcoal  could  only  be  secured  by  removing  the  hydro- 
carbon which  he  assumed  to  be  present  after  carbonization. 
Being  difficultly  volatile,  these  hydrocarbons  prevent  the  adsorp- 
tion of  other  gases  or  vapors  on  the  active  material.  To  prove 
this,  red  cedar  charcoal  was  heated  in  a  bomb  connected  with  a 
pump  which  drew  air  through  the  bomb.  Although  the  charcoal 
had  been  carbonized  at  800°,  various  gases  and  vapor  began  to 


242  CHEMICAL    WARFARE 

come  off  at  300°,  and  when  cooled,  condensed  to  crystalline 
plates. 

This  experiment  not  only  proved  the  existence  of  com- 
ponents containing  hydrogen  in  the  charcoal,  but  also  showed 
that  one  way  of  removing  the  hydrocarbon  film  on  the  active 
carbon  was  to  treat  with  an  oxidizing  agent. 

In  the  light  of  the  later  experimental  work  Chaney  feels 
that  there  are  two  forms  of  elementary  carbon — ** active*'  and 
** inactive";  the  active  form  is  characterized  by  a-  high  specific 
adsorptive  capacity  for  gas  while  the  inactive  form  lacks 
this  property.  In  general  the  temperature  of  formation  of 
the  active  form  is  below  500-600°  C.  The  form  is  easily 
attacked  by  oxidizing  agents — while  the  latter  is  relatively 
stable.  The  combination  of  active  carbon  with  an  adsorbed 
layer  or  layers  of  hydrocarbon  is  known  as  ** primary"  carbon. 
Anthracite  and  bituminous  coal  are  native  primary  carbons, 
while  coke  contains  a  considerable  amount  of  inactive  carbon, 
resulting  from  the  decomposition  of  hydrocarbon  during  its 
preparation. 

Preparation  of  Active  Charcoal 

"On  the  basis  of  the  above  discussion,  the  preparation  of  active 
charcoal  will  evidently  involve  two  steps: 

"First. — The  formation  of  a  porous,  amorphous  base  carbon  at  a 
relatively  low  temperature. 

"Second. — The  removal  of  the  adsorbed  hydrocarbons  from  the 
primary  carbon,  and  the  increase  of  its  porosity. 

"The  first  step  presents  no  very  serious  difficulties.  It  involves, 
in  the  case  of  woods  and  similar  materials,  a  process  of  destructive 
distillation  at  relatively  low  temperatures.  The  deposition  of  inactive 
carbon,  resulting  from  the  cracking  of  hydrocarbons  at  high  tempera- 
tures, must  be  avoided.  The  material  is  therefore  charged  into  the 
retorts  in  thin  layers,  so  that  the  contact  of  the  hydrocarbon  vapors 
with  hot  charcoal  is  avoided  as  much  as  possible.  Furthermore,  most 
of  the  hydrocarbon  is  removed  before  dangerous  temperatures  are 
reached.  A  slight  suction  is  maintained  to  prevent  outward  leaks,  but 
no  activation  by  oxidation  is  attempted,  as  this  can  be  carried  on  under 
better  control  and  with  less  loss  of  material  in  a  separate  treatment. 

"The  second  step,  that  is,  the  removal  of  the  absorbed  hydrocarbons 
from  the  primary  carbon,  is  a  much  more  difficult  matter.    Prolonged 


ABSORBENTS 


243 


heating,  at  sufficiently  high  temperatures,  is  required  to  remove  or 
break  up  the  hydrocarbon  residues.  On  the  other  hand,  volatilization 
and  cracking  of  the  hydrocarbons  at  high  temperatures  is  certain  to 
produce  an  inactive  form  of  carbon  more  or  less  like  graphite  in  its 
visible  characteristics,  which  is  not  only  inert  and  non-adsorbent,  but 
is  also  highly  resistant  to  oxidation.     The  general  method  of  procedure 


Combustion, 
Gaa  Exit 


Charcoal 
Intake  Valve 


Superheated  Steam 
Exit  to  Furnace 


IP 

^^vhich  has  yielded  the  best  results,  is  to  remove  the  adsorbed  hydro- 
^Htrbons  by  various  processes  of  combined  oxidation  and  distillation, 
^■^hereby  the  hydrocarbons  of  high  boiling  points  are  broken  down  into 
^^Bore  volatile  substances  and  removed  at  lower  temperatures,  or  under 
^Hpnditions  less  likely  to  result  in  subsequent  deposition  of  inactive 
^Htrbon.  Thin  layers  of  charcoal  and  rapid  gas  currents  are  used  so 
^^■at  contact  between  the  volatilized  hydrocarbons  and  the  hot  active 


|G.  67.     Dorsey  Reactor  for  Activating  Cocoanut  Charcoal  with  Steam. 


244  CHEMICAL  WARFARE 

hydrocarbons  at  high  temperature,  with  consequent  deposition  of  in- 
active carbon,  is  largely  avoided. 

"While  the  removal  of  the  hydrocarbons  by  oxidation  and  dis- 
tillation is  the  main  object  of  the  activation  process,  another  important 
action  goes  on  at  the  same  time,  namely,  the  oxidation  of  the  primary 
carbon  itself.  This  oxidation  is  doubtless  advantageous,  up  to  a 
certain  point,  for  it  probably  at  first  enl'arges,  at  the  expense  of  the 
walls  of  solid  carbon,  cavities  already  present  in  the  charcoal,  thus 
increasing  the  total  surface  exposed.  Moreover,  the  outer  ends  of 
the  capillary  pores  and  fissures  must  be  somewhat  enlarged  by  this 
action  and  a  readier  access  thus  provided  to  the  inner  portions  of 
the  charcoal.  However,  as  soon  as  the  eating  away  of  the  carbon 
wall  begins  to  unite  cavities,  it  decreases,  rather  than  increases,  the 
surface  of  the  charcoal,  and  a  consequent  drop  in  volume  activity, 
that  is  in  the  service  time,  of  the  charcoal,  is  found  to  result. 

"It  is  obvious,  therefore,  that  conditions  of  activation  must  be  so 
chosen  and  regulated  as  to  oxidize  the  hydrocarbons  rapidly  and  the 
primary  carbon  slowly.  Such  a  differential  oxidation  is  not  easy  to 
secure  since  the  hydrocarbons  involved  have  a  very  low  hydrogen 
content,  and  are  not  much  more  easily  oxidized  than  the  primary 
carbon  itself.  Furthermore,  most  of  the  hydrocarbons  to  be  removed 
are  shut  up  in  the  interior  of  the  granule.  On  the  one  hand,  a  high 
enough  temperature  must  be  maintained  to  oxidize  the  hydrocarbons 
with  reasonable  speed;  on  the  other  hand,  too  high  a  temperature 
must  not  be  employed,  else  the  primary  carbon  will  be  unduly  con- 
sumed. The  permissible  range  is  a  relatively  narrow  one,  only  about 
50  to  75°.  The  location  of  the  optimum  activating  temperature  depends 
upon  the  oxidizing  agent  employed  and  upon  other  variables  as  well; 
for  air,  it  has  been  found  to  lie  somewhere  between  350  and  450°,  and 
for  steam  between  800  and  1000°. 

"The  air  activation  process  has  the  advantage  of  operating  at  a 
conveniently  low  temperature.  It  has  the  disadvantage,  that  local 
heating  and  an  excessive  consumption  of  primary  carbon  occur,  so 
that  a  drop  in  volume  activity  results  from  that  cause  before  the 
hydrocarbons  have  been  completely  eliminated.  As  a  consequence, 
charcoal  of  the  highest  activity  cannot  be  obtained  by  the  air  activation 


The  steam  activation  process  has  the  disadvantage  that 
it  operates  at  so  high  a  temperature  that  the  regulation  of 
temperature  becomes  difficult  and  other  technical  difficulties 
are  introduced.     It  has  the  advantage  that  local  heating  is 


ABSORBENTS 


245 


eliminated.  The  hydrocarbons  can,  therefore,  be  largely 
removed  without  a  disproportionate  consumption  of  primary 
carbon.  This  permits  the  production  of  a  very  active  charcoal. 
It  has  the  further  advantage  that  it  worked  well  with  all 
kinds  of  charcoal.  Inferior  material,  when  treated  with  steam, 
gave  charcoal  nearly  as  good  as  the  best  steam  treated  cocoanut 
charcoal.  Because  of  the  shortage  of  cocoanut,  this  was  a  very 
important  consideration. 


I 


Fig.  68. — Section  of  Raw  Cocoanut  Shell.     Magnified  146^  diameters. 

The  air,  steam  and  also  carbon  dioxide-steam  activation 
*ocesses  have  all  been  employed  on  a  large  scale  by  the 
lemical  Warfare  Service  for  the  manufacture  of  gas  mask 
irbon. 

"The  above  considerations  are  illustrated  fairly  well  by  the  photo- 
micro^aphs  shown  in  Figs.  68  to  71.  Fig.  68  shows  a  section  of 
the  original  untreated  cocoanut  shell  crosswise  to  the  long  axis  of  the 
shell.     In  it   can  be   seen  the   closely   packed,   thick-walled   so-called 


246 


CHEMICAL   WARFARE 


Fig.  69. — Section  of  Carbonized  Cocoanut  Charcoal. 
Magnified  146^  Diameters. 


Fig.  70. — Two- Minute  Charcoal  not  Activated. 
Magnified  732  Diameters. 


ABSORBENTS 


2A1 


'stone-cells^  characteristic  of  all  hard  and  dense  nut  shells.  Fig.  69 
is  a  photograph  of  a  similar  section  through  the  same  cocoanut  shell 
after  it  has  been  carbonized.  As  these  photographs  are  all  taken  with 
vertical  illumination  against  a  dark  background,  the  cavities,  or  voids, 
and  depressions  all  apiJear  black,  while  the  charcoal  itself  appears 
white.  It  is  clear  from  this  i^hotograph  that  much  of  the  original 
grosser  structure  of  the  slicU  persists  in  the  carbonized  products.  Figs. 
70  and  71  are  more  highly  magnified  photographs  of  a  carbonized 
cliarcoal  before  and  after  activation,  respectively.     As  before,  all  the 


Fig.  71. — 31-Minute  Steam  Activated  Charcoal. 
Magnified  732  Diameters. 

dark  areas  represent  voids  of  little  or  no  importance  in  the  adsorptive 
activity  of  the  charcoal,  while  the  white  areas  represent  the  charcoal 
itself.  In  Fig.  70  (unactivated)  the  charcoal  itself  between  the  voids 
it  seen  to  be  relatively  compact,  while  in  Fig.  71  (activated)  it  is 
decidedly  granular.  This  granular  structure,  just  visible  at  this  high 
magnification  (1000  diameters),  probably  represents  the  grosser  porous 
ructure  on  which  the  adsorption  really  depends.  These  photographs, 
jrefore,  show  how  the  porosity  is  increased  by  activation." 


The  great  demand  for  charcoal,  and  the  need  for  activating 
ler  than  cocoanut  charcoal  led  to  the  development  of  the 


248 


CHEMICAL  WARFARE 


Dressier  tunnel  kiln,  which  seemed  to  offer  many  advantages 
over  the  Dorsey  type  of  treater. 

"The  Dressier  tunnel  kiln  is  a  type  used  in  general  ceramic  work. 
The  furnace  consists  essentially  of  a  brick  kiln  about  190  ft.  long, 
12  ft.  broad,  and  9  ft.  high,  Hned  with  fire  brick.     Charcoal  is  loaded 


Fire  Brick 


Development  Division 

CHEMICAL  WARFARE  SERVICE  U.S.A. 

Defense  Department 

NELA    PARK,    CLEVELAND 

SECTIONAL  VIEW  OF 
DRESSIER  TUNNEL  KILN 

Drawn  by  Fiivate  C.  R.  Gai-thwait 
October  IGth  '18 


Fig.  72. — Sectional  View  of  Dressier  Tunnel  Kiln,  Adapted  to  Activation  of 

Charcoal. 


in  shallow,  refractory  trays  in  small  tram  cars,  about  120  trays  to 
the  car.  The  cars  enter  the  kiln  through  a  double  door  and  the 
charcoal  remains  in  the  hot  zone  at  a  temjaerature  of  about  850°  C. 
for  about  4  hrs.,  depending  upon  the  nature  of  the  material  charged. 
Water  is  atomized  into  this  kiln,  and  a  positive  pressure  maintained 
in  order  to  exclude  entrance  of  air.  The  kiln  is  gas-fired  and  the 
charcoal  is  activated  by  the  steam  in  the  presence  of  the  combustion 
gases. 


ABSORBENTS  249 

"Under  such  treatment  the  charcoal  is  given  a  high  degree  of 
activation  without  the  usual  accompanying  high  losses.  Seemingly  the 
oxidizing  medium  used,  together  with  the  operating  conditions,  produce 
a  deep  penetration  of  tlie  charcoal  particles  without  increasing  the 
extensive  surface  combustion  experienced  in  the  steam  activators.  The 
capacity  of  such  a  type  furnace  is  limited  only  by  the  size  of  the 
installation. 

"The  advantages  of  this  type  furnace  may  be  tabulated  as  follows: 

1 — High  quality  of  product. 

2 — Small  weight    and    volume   losses. 

3 — Large  capacity  per  unit. 

4 — Minimum  initial  cost  and  maintenance  of  installation. 

5 — Simplicity  and  cheapness  of  operation. 

6 — Adaptability  to  activation  of  all  carbon  materials. 

7 — Availability  of  furnaces  of  this  general  type  already  constructed." 


Substitutes  for  Nut  Charcoal 

The  first  experiments  were  made  with  a  special  anthracite 
coal  (non-laminated  and  having  conchoidal  fracture).  This 
had  a  life  of  560  minutes  as  against  360  minutes  for  air  treated 
cocoanut  charcoal  and  800-900  minutes  for  steam  treated  char- 
coal. 

When  the  Gas  Defense  Service  tried  to  activate  anthracite 
on  a  large  scale  in  vertical  gas  retorts  at  Derby,  Connecticut, 
the  attempt  was  a  failure.  They  carbonized  at  900°  and  then 
turned  on  the  steam  with  the  result  that  the  steam-treated 
coal  had  a  slightly  greater  density  than  the  untreated,  which 
was  wrong,  and  had  a  shiny  appearance  in  parts  with 
roughened  deposits  in  other  parts.  When  the  hydrocarbons 
are  decomposed  at  high  temperatures,  the  resulting  carbon 
ii?  somewhat  graphitic,  is  itself  inactive,  is  not  readily  oxidized, 
and  impairs  or  prevents  the  activation  of  the  normal  carbon 
upon  which  it  is  deposited.  This  discovery  made  it  possible 
to  treat  anthracite  successfully.  The  conditions  must  be  such 
as  to  minimize  high-temperature  cracking,  to  carry  off  or 
oxidize  the  hydrocarbons  as  fast  as  formed,  and  especially 
to  prevent  the  gases  from  cooler  portions  of  the  treater  coming 


250  CHEMICAL  WARFARE 

in  contact  with  carbon  at  a  much  higher  temperature.  With 
these  facts  in  mind,  a  plant  was  built  at  Springfield  which 
produced  10  tons  a  day  of  150-300  minute  charcoal  from  raw 
anthracite.  This  was  one-third  of  the  total  production  at  that 
time  and  was  mixed  with  the  nut  charcoal  made  at  Astoria, 
thereby  preventing  an  absolute  shortage  of  canister-filling 
material  in  October,  1918. 

It  was  next  shown  that  the  cocoanut  charcoal  fines  result- 
ing from  grinding  and  screening  losses  and  amounting  to  50 
per  cent  of  the  product,  could  be  very  finely  ground,  mixed 
with  a  binder,  and  baked  like  ordinary  carbon  products.  By 
avoiding  gas-treating  in  the  bake,  the  resulting  charcoal  is 
nearly  as  good  as  that  from  the  original  shell.  A  recovery 
plant  for  treating  the  cocoanut  fines  was  built  at  Astoria.  The 
product  was  called  ''Coalite." 

The  great  advantage  of  cocoanut  shell  as  a  source  of  char- 
coal is  that  it  is  very  dense  and  consequently  it  is  possible 
to  convert  it  into  a  mass  having  a  large  number  of  fine  pores, 
whereas  a  less  dense  wood,  like  cedar,  will  necessarily  give 
more  larger  pores,  which  are  of  relatively  little  value.  The 
cocoanut  charcoal  is  also  pretty  resistant  to  oxidation  which 
seems  to  make  selective  oxidation  a  more  simple  matter.  By 
briquetting  different  woods,  it  is  possible  to  make  charcoal 
from  them  which  is  nearly  equal  to  that  from  cocoanut  shell. 

By  heating  lamp  black  with  sulfur  and  briquetting,  it 
was  possible  to  make  a  charcoal  having  approximately  the 
same  service  time  as  cocoanut  charcoal.  A  charcoal  was  made 
by  emulsifying  carbon  black  with  soft  pitch,  which  gave  the 
equivalent  of  400  minutes  against  chloropicrin  before  it  had 
been  steam-treated.  This  looked  so  good  that  the  plans  were 
drawn  for  making  a  thousand  pounds  or  more  of  this  product 
at  Washington  to  give  it  a  thorough  test.  This  was  not  done 
on  account  of  the  cessation  of  all  research  work.  The  possible 
advantage  of  this  product  was  the  more  uniform  distribution 
of  binder. 

Instead  of  steam-treating  anthracite  coal  direct,  it  was 
also  pulverized,  mixed  with  a  binder,  and  baked  into  rods 
which  were  then  ground  and  activated  with  steam.    The  result- 


ABSORBENTS  251 

iiig  material,  which  was  known  as  Carbonite,  had  somewhat 
less  activity  than  the  lamp-black  mixes  but  was  very  much 
cheaper.  A  plant  was  built  to  bake  40  tons  a  day  of  this 
material,  which  would  yield  10  tons  a  day  of  active  carbon 
after  allowing  for  grinding  losses  and  steam  treatment.  The 
plant  was  guaranteed  to  furnish  an  absorbent  having  a  life 
of  600  minutes  against  chloropicrin. 

German  Charcoal 

After  the  Armistice  was  signed,  Chancy  took  up  the  ques- 
tion of  how  the  Germans  made  their  charcoal.  The  German 
charcoal  was  made  from  coniferous  wood  and  was  reported 
to  be  as  good  as  ours,  in  spite  of  the  fact  that  they  were 
using  inferior  materials.  Inside  of  a  month  Chancy  had  found 
out  how  the  German  charcoal  was  made,  had  duplicated  their 
material,  and  had  shown  that  it  was  nothing  like  as  good  as 
our  charcoal.  The  Germans  impregnated  the  wood  with  zinc 
chloride,  carbonized  at  red  heat,  and  washed  out  most  of  the 
zinc  chloride.  When  this  zinc  chloride  was  found  in  the  Ger- 
man charcoal,  it  was  assumed  that  it  had  been  added  after 
the  charcoal  had  been  made.  It  was  therefore  dissolved  out 
with  hydrochloric  acid,  thereby  improving  the  charcoal  against 
chloropicrin.  The  German  charcoal  was  then  tested  as  it 
stood,  including  the  fines,  against  American  charcoal,  8  to  14 
mesh.  The  most  serious  error,  however,  was  in  testing  only 
against  a  high  concentration  of  chloropicrin.  The  German 
charcoal  contains  relatively  coarse  pores  which  condense  gases 
at  high  concentrations  very  well  but  which  do  not  absorb 
gases  strongly  at  low  concentrations.  The  result  was  that 
the  German  charcoal  was  rated  as  being  four  or  five  times 
as  good  as  it  really  was. 

Comparison  of  Charcoal 

The  following  table  shows  a  comparison  of  charcoals  from 
different  sources.    The  method  of  activation  was  identical  and 


German  Charcoal.     X200. 


252 


Fig.  73. — Charcoal  from  Spruce  Wood. 


ABSORBENTS 


253 


the  times  of  treatment  were  those  approximately  giving  the 
highest  service  time.  The  results  against  chloropicrin,  there- 
fore, represent  roughly  the  relative  excellence  of  the  charcoal 
obtainable  from  various  raw  materials,  using  this  method  of 
activation : 

Comparison  of  Various  Active  Charcoals  Activated  in  Laboratory 


Base  Material 

Apparent 
Density 

Steam  Treat- 
ment at  900° 

Accelerated 
Chloropicrin 
Test  Results 

Primary 
Carbon 

Activated 
Carbon 

Time 
Min. 

Weight 

Loss 
Per  Cent 

Weight 
Absorbed 
Per  Cent 

Service 
Time 
Min. 

Sycamore 

0.158 
0.223 
0.420 
0.465 
0.520 
0.700 
0.659 
0.540 
0.710 
0.710 

0.080 
0.097 
0.236 
0.331 
0.316 
0.460 
0.502 
0.322 
0.445 
0.417' 

18 

60 

60 

60 

120 

120 

120 

210 

120 

180 

53 
88 
44 
44 
71 
70 
48 
68 
60 
75 

41 
78 
32 
31 
46 
48 
51 
85 
61 
72 

7.3 

Cedar. . 

16.0 

Mountain  mahogany 
Ironwood 

16.3 
20.8 

Brazil  nut 

32.2 

Ivory  nut 

47.0 

Cohune  nut 

Babassu  nut 

Cocoanut 

53.4 

58.7 
58.4 

Cocoanut 

64.4 

Briquetted  Materials 


Sawdust 

Carbon  black .  . 
Bituminous  coal 
Anthracite  coal. 


0.542 

0.365 

120 

66 

53 

0.769 

0.444 

240 

64.3 

53 

0.789 

0.430 

165 

61 

58.3 

0.830 

0.371 

480 

81 

53 

40.0 
50.5 
46.8 
40.7 


"In  conclusion,  it  will  be  of  interest  to  compare  the  charcoals  manu- 
factured and  used  by  the  principal  belligerent  nations,  both  with  one 
another  and  with  the  above-mentioned  laboratory  preparations.  Data 
on  these  charcoals  are  given  in  the  following  table: 


254 


CHEMICAL  WARFARE 


Comparison  of  Typical  Production  Charcoals  of  the  Principal 
Belligerent  Nations 


Country 

Date 

United  States 

Nov.  1917 

United  States 

June,  1918 

United  States 

Nov.  1918 

England 

1917 

England 

Aug.  1918 

France 

1917-18 

Germany 

Early 

Germany 

June,  1917 

Germany 

June,  1918 

Raw  Material 


Cocoauut 

Mixed  nuts,  etc. . 

Cocoanut 

Wood 

Peach  stones,  etc. 

Wood 

Wood 

Wood 

Wood 


Appar- 
ent 
Den- 
sity 


0.60 
0.58 
0.51 
0.27 
0.54 
0.23 
? 

0.25 
0.24 


Service 
Time 
Corr. 

to  8-14 
Mesh 


10 

18 

34 

6 

16 

2 

3 

33 

42 


Remarks 


Air  activated 
Steam  activated 
Steam  activated 
Long  distillation 


Chemical  and 
steam  treatment 

Chemical  and 
steam  treatment 

Chemical  and 
steam  treatment 


"It  is  at  once  evident  that  the  service  time  of  most  of  these 
charcoals  is  very  much  less  than  was  obtained  with  the  laboratory 
samples.  However,  in  the  emergency  production  of  this  material  on 
a  large  scale,  quantity  and  speed  were  far  more  important  than  the 
absolute  excellence  of  the  product.  It  will  be  noted,  for  instance, 
that  the  cocoanut  charcoal  manufactured  by  the  United  States,  even  in 
November,  1918,  was  still  very  much  inferior  to  the  laboratory  samples 
made  from  the  same  raw  material.  This  was  not  because  a  very  active 
charcoal  could  not  be  produced  on  a  large  scale,  for  even  in  May, 
1918,  the  possibility  of  manufacturing  a  50-min.  charcoal  on  a  large 
scale  had  been  conclusively  demonstrated,  but  this  activation  would 
have  required  two  or  three  times  as  much  raw  material  and  five  times 
as  much  apparatus  as  was  then  available,  due  to  the  much  longer  time 
of  heating,  and  the  greater  losses  of  carbon  occasioned  thereby. 

"It  should  furthermore  be  pointed  out  that  the  increase  in  the 
chloropicrin  service  time  of  charcoal  from  18  to  50  min.  does  not 
represent  anything  like  a  proportionate  increase  in  its  value  under 
field  service  conditions.  This  is  partly  due  to  the  fact  that  the  increased 
absorption  on  the  high  concentration  tests  is  in  reality  due  to  con- 
densation in  the  capillaries,  which,  as  has  been  pointed  out,  is  not  of 
much   real   value.     More   important   than   this,   however,   is   the   fact 


absorbent;s 


255 


that  most  of  the  important  gases  used  in  warfare  are  not  held  by 
adsorption  only,  but  by  combined  adsorption  and  chemical  reaction, 
for  which  purpose  an  18-min.  charcoal  is,  in  general,  almost  as  good 
as  a  50-min.  charcoal." 

Typical  Absorptive  Values  of  Different  Charcoals  Against  Various 

Gases 


Charcoal 

Nation 

a 

c 
o 
O 

o 

II 

Service  Time,  Minutes 
Standard  Conditions 

No. 

a 
3 

1 

'H 

.s 

2 

< 

If 

IS 

.2-g 

•i 

1 

Poor  cocoanut. . .  . 

U.  S.  A. 

0 

10 

120 

175 

20 

18 

55 

50 

270 

2 

Medium  cocoanut 

U.  S.  A. 

0 

30 

350 

260 

25 

25 

65 

65 

370 

3 

Good  cocoanut. . . 

U.  S.  A. 

0 

60 

620 

310 

27 

30 

75 

70 

420 

4 

Same  as  No.  2  but 

wet 

U.  S.  A. 

12 

18 

320 

330 

35 

16 

35 

95 

5 

No.  2  impregnated 

U.  S.  A. 

0 

35 

400 

700 

70 

400 

70 

190 

510 

'6 

Wood 

French 
British 
British 

0 
0 
0 

2.5 

6 

16 

25 

70 

190 

75 

90 

135 

9 
18 
30 

0 

4 

25 

1 

5 

65 

20 
30 
60 

7 

Wood 

8 

Peach  stone 

9 

Treated  wood 

German 

0 

42 

230 

105 

20 

20 

22 

25 

10 

No.  9  impregnated 

German 

30 

9 

90 

320 

16 

1 

110 

120 

Standard  Conditions  of  Tests 

Mesh  of  absorbent 8-14 

Depth  of  absorbent  layer 10  cm. 

Rate  of  flow  per  sq.  cm.  per  min 500  cc. 

Concentration  of  toxic  gas. 0.1  per  cent 

Relative  humidity     50  per  cent 

Temperature 20° 

Results  expressed  in  minutes  to  the  99  per  cent  efficiency  points. 

Results  corrected  to  uniform  concentrations  and  size  of  particles. 


Soda  Lime 


Charcoal  is  not  a  satisfactory  all  round  absorbent  because 
it  has  too  little  capacity  for  certain  highly  volatile  acid  gases, 
such  as  phosgene  and  hydrocyanic  acid,  and  because  oxidizing 


256  CHEMICAL  WARFARE 

agents  are  needed  for  certain  gases.  To  overcome  these  defi- 
ciencies the  use  of  an  alkali  oxidizing  agent  in  combination 
with  the  charcoal  has  been  found  advisable.  The  material 
actually  used  for  this  purpose  has  been  granules  of  soda  lime 
containing  sodium  permanganate.  Its  principal  function  may 
be  said  to  be  to  act  as  a  reservoir  of  large  capacity  for  the 
permanent  fixation  of  the  more  volatile  acid  and  oxidizable 
gases. 

The  development  of  a  satisfactory  soda  lime  was  a  difficult 
problem.  The  principal  requirements  follow :  Its  activity  is  not 
of  vital  importance,  as  the  charcoal  is  able  to  take  up  gas  with 
extreme  rapidity  and  then  later  give  it  off  more  slowly  to  the 
soda  lime.  Ahsoiytive  capacity  is  of  the  greatest  importance, 
since  the  soda  lime  is  relied  upon  to  hold  in  chemical  combination 
a  very  large  amount  of  toxic  gas.  Both  chemical  stability  and 
mechanical  strength  are  difficult  to  attain.  The  latter  had  never 
been  solved  until  the  war  made  some  solution  absolutely 
imperative. 

Composition  of  Regular  Army  Soda-Lime 

The  exact  composition  of  the  army  soda-lime  has  under- 
gone considerable  modification  from  time  to  time  as  it  has 
been  found  desirable  to  change  the  raw  materials  or  the  method 
of  manufacture.  A  rough  average  formula  which  will  serve 
to  bring  out  the  interrelation  between  the  different  consti- 
tuents is  as  follows: 

CoMrosiTiON  OF  Wet  Mix 

Per  Cent 

Hydrated  lime 45 

Cement 14 

Kieselguhr 6 

Sodium  hydroxide 1 

Water 33  (approx.) 

After  Drying 

Moisture  content 8  (approx.) 

After  Spraying 

Moisture  content 13  (approx.) 

Sodium  permanganate  content 3  (approx.) 


ABSORBENTS  257 

Within  limits,  the  method  of  manufacture  is  more  important 
than  the  composition  or  other  variables,  and  has  been  the 
subject  of  a  great  deal  of  research  work  even  on  apparently 
minor  details.  The  process  finally  adopted  consists  essentially 
in  making  a  plastic  mass  of  lime,  cement,  kieselguhr,  caustic 
soda,  and  water,  spreading  in  slabs  on  wire-bottomed  trays, 
allowing  to  set  for  2  or  3  days  under  carefully  controlled 
conditions,  drying,  grinding,  and  screening  to  8-14  mesh,  and 
finally  spraying  witli  a  strong  solution  of  sodium  permanganate 
with  a  specially  designed  spray  nozzle.  The  spraying  process 
h  a  recent  development,  most  of  the  soda-lime  having  been 
made  by  putting  the  sodium  permanganate  into  the  original 
wet  mix.  Many  difficulties  had  to  be  overcome  in  developing 
the  spraying  process,  but  it  eventually  gave  a  better  final 
product,  and  resulted  in  a  large  saving  of  permanganate  whicli 
was  formerly  lest  during  drying,  in  fines,  etc. 

Function  of  Different  Components 

Lime.  The  hydrated  lime  furnishes  the  backbone  of  the 
absorptive  properties  of  the  soda  lime.  It  constitutes  over 
50  per  cent  of  the  finished  dry  granule  and  is  re  sponsible  in 
a  chemical  sense  for  practically  all  the  gas  absorption. 

Cement.  Cement  furnishes  a  degree  of  hardness  adequate 
to  witlistand  service  conditions.  It  interferes  somewhat  with 
the  absortive  properties  of  the  soda  lime  and  it  is  an  open 
question  whether  the  gain  in  hardness  produced  by  its  use 
is  valuable  enough  to  compensate  for  the  decreased  absorption 
which  results. 

Kieselguhr.  The  loss  in  absorptive  capacity  due  to  the 
presence  of  cement  is  in  part  counterbalanced  by  the  simul- 
taneous introduction  of  a  relatively  small  weight  though  con- 
siderable bulk,  of  kieselguhr.  In  some  cases,  there  seems  to 
be  a  reaction  between  the  lime  and  the  kieselguhr,  which 
results  in  some  increase  in  hardness. 

Sodium  Hydroxide.  Sodium  hydroxide  has  two  primary 
functions  in  the  soda  lime  granule.  In  the  first  place,  a  small 
amount  serves  to  give  the  granule  considerable  more  activity. 
The  second  function  is  to  maintain  roughly  the  proper  moisture 


258  CHEMICAL  WARFARE 

content.  This  water  content  (roughly  13-14  per  cent  after 
spraying)  is  very  important,  in  order  that  the  maximum  gas 
absorption  may  be  secured. 

Sodium  Permang'anate.  The  function  of  the.  sodium  per- 
manganate is  to  oxidize  certain  gases,  such  as  arsine,^  and  to 
act  as  an  assurance  of  protection  against  possible  new  gases. 
The  purity  of  the  sodium  permanganate  solution  used  was 
found  to  be  one  of  the  most  important  factors  in  making  stable 
soda  lime.  It  was,  therefore,  necessary  to  work  out  special 
methods  for  its  manufacture.  Two  such  methods  were  devel- 
oped, and  successfully  put  into  operation. 

Careful  selection  of  other  material  is  also  necessary,  and 
this  phase  of  the  work  contributed  greatly  to  the  final  develop- 
ment of  the  form  of  soda  lime. 

^  Which,  however,  was  never  used  on  the  battlefield. 


CHAPTER   XIV 

TESTING  ABSORBENTS  AND   GAS  MASKS 

One  of  the  first  necessities  in  the  development  of  absorbents 
and  gas  masks  was  a  method  of  testing  them  and  comparing 
their  deficiencies.  While  the  ultimate  test  of  the  value  of 
an  absorbent,  canister  or  facepiece  is,  of  course,  the  actual 
man  test  of  the  complete  mask,  the  time  consumed  in  these 
tests  is  so  great  that  more  rapid  tests  were  devised  for  the 
control  of  these  factors  and  the  man  test  used  as  a  .check  of 
the  purely  mechanical  methods. 

Testing  op  Absorbents  ^ 

Absorbents  should  be  tested  for  moisture,  hardness,  uni- 
formity of  sample  and  efficiency  against  various  gases. 

Moisture  is  simply  determined  by  drying  for  two  hours  at 
150°.    The  loss  in  weight  is  called  moisture. 

The  liardness  or  resistance  to  abrasion  is  determined  by  shak- 
ing a  50-gTam  sample  with  steel  ball  bearings  for  30  minutes 
on  a  Ro-tap  shaking  machine.  The  material  is  then  screened 
and  the  hardness  number  is  determined  by  multiplying  the 
weight  of  absorbent  remaining  on  the  screen  by  two. 

The  efficiency  of  an  absorbent  against  various  gases  depends 
upon  a  variety  of  factors.  Because  of  this,  it  is  necessary 
to  select  standard  conditions  for  the  test.  These  were  chosen 
as  follows: 

The  absorbent  under  test  is  filled  into  a  sample  tube  of 
specified  diameter  (2  cm.)  to  a  depth  of  10  cm.  by  the  standard 
method  for  filling  tubes,  and  a  standard  concentration  (usually 
1,000  or  10,000  p.p.m.  by  volume)  of  the  gas  in  air  of  definite 
(50  per  cent)   humidity  is  passed  through  the  absorbent  at 

*Sec  Fieldner  and  others,  J.  Ind.  Eng.  Chem.,  11,  519  (1919). 

259 


260  CHEMICAL    WARFARE 

a  rate  of  500  cc.  per  sq.  cm.  per  min.  The  concentration  of 
the  entering  gas  is  determined  by  analysis.  The  length  of  time 
is  noted  from  the  instant  the  gas-air  mixture  is  started  through 
the  absorbent  to  the  time  the  gas  or  some  toxic  or  irritating 
reaction  product  of  the  gas  begins  to  come  through  the 
absorbent,  as  determined  by  some  qualitative  test.  Quantita- 
tive samples  of  the  outflowing  gas  are  then  taken  at  known 
intervals  and  from  the  amount  of  gas  found  in  the  sample 
the  per  cent  efficiency  of  the  absorbent  at  the  corresponding 
time  is  calculated. 
Per  cent  efficiency  = 

p.p.m.   entering  gas  —  p.p.m.   effluent   gas 


p.p.m.  entering  gas 


xioo. 


These  efficiencies  are  plotted  against  the  minutes  elapsed  from 
the  beginning  of  the  test  to  the  middle  of  the  sampling  period 
corresponding  to  that  efficiency  point.  A  smooth  curve  is 
drawn  through  these  points  and  the  efficiency  of  the  absorbent 
is  reported  as  so  many  minutes  to  the  100,  99,  95,  90,  80,  etc., 
per  cent  efficiency  points. 

The  apparatus  used  in  carrying  out  this  test  is  shown  in 
Fig.  74.  Descriptive  details  may  be  found  in  the  article  by 
Fieldner  in  TJie  Journal  of  Industrial  and  Engineering  Chem- 
istry for  June,  1919.  With  modifications  for  high  and  low 
boiling  materials,  the  apparatus  is  adapted  to  such  a  variety 
of  gases  as  chlorine,  phosgene,  carbon  dioxide,  sulfur  dioxide, 
hydrocyanic  acid,  benzyl  bromide,  chloropicrin,  superpalite, 
etc. 

As  the  quality  of  the  charcoal  increased,  the  so-called 
standard  test  required  so  long  a  period  that  an  accelerated 
test  was  devised.  In  this  the  rate  was  increased  to  1,000  cc. 
per  minute,  the  relative  humidity  of  the  gas-air  mixture  was 
decreased  to  zero,  and  the  concentration  was  about  7,000  p.p.m. 
The  rate  is  obtained  by  using  a  tube  with  an  internal  diameter 
of  1.41  cm.  instead  of  2.0  cm. 

Canisters 

After  an  absorbent  has  been  developed  to  a  given  point, 
and  is  considered  of  sufficient  value  to  be  used  in  a  canister, 


TESTING  ABSORBENTS  AND  GAS  MASKS 


261 


the  materials  are  assembled  as  described  in  Chapter  XII. 
While  the  final  test  is  the  actual  use  of  the  canister,  machine 
tests  have  been  devised  which  give  valuable  information 
regarding  the  value  of  the  absorbent  in  the  canister  and  the 
lethod  of  filling. 


Ficj.  74. — Standard  Two-tube  Apparatus  for  Testing  Absorbents,  Showing 
Arrangement  for  Gases  Stored  in  Cylinders.    ;    <  i    ,    . 

The  first  test  must  be  that  for  leakage.  The  canister  must 
show  no  signs  of  leaking  when  submitted  to  an  air  pressure 
of  15  inches  of  mercury  (about  lialf  of  the  normal  atmospheric 
pressure). 

The  second  factor  tested  is  the  resistance  to  air  flow.  This 
is  determined  at  a  flow  of  85  liters  per  minute  and  should 


262 


CHEMICAL  WARFARE 


not  exceed  3  inches.     The  latest  canister  design  has  a  much 
lower  resistance  (from  2  to  2i/^  inches). 

The  third  test  is  the  efficiency  of  the  canister  against  various 
gases.  For  routine  work,  phosgene,  chloropicrin  and  hydro- 
cyanic acid  are  used  against  the  standard  mixture  of  charcoal 
and  soda  lime:  Chloropicrin  is  usually  used  against  straight 
charcoal  fillings,  while  phosgene  and  hydrocyanic  acid  are  used 
against  soda  lime. 


Water  Batb 


Mixing  Cbamber 


Fig.  75. — Apparatus  for  Testing  Canisters  Against  Chloropicrin. 


Different  types  of  apparatus  are  required  for  these  gases. 
They  are  very  complicated,  as  may  be  seen  from  the  sketch 
in  Fig.  75,  and  yet  a  man  very  quickly  learns  the  procedure 
necessary  to  carry  out  a  test  of  this  kind.  The  gas  is  passed 
through  the  canister  under  given  conditions,  until  at  the  end 
of  the  apparatus  a  test  paper  or  solution  indicates  that  the 
gas  is  no  longer  absorbed  but  is  passing  through  unchanged. 
This  point  is  called  the  ''break  point,"  and  the  time  required 
to  reach  this  point  is  known  as  the  life  of  the  canister.  This 
time  is  also  the  time  to  100  per  cent  efficiency.     Other  points, 


r 


TESTING  ABSORBENTS  AND  GAD  MASKS  263 


m 


I 


such  as  99,  95,  90  and  80  per  cent  efficiency  are  determined. 
These  are  used  in  comparing  canisters. 

The  canister  tests  were  of  two  general  classes:  continuous 
and  intermittent.  In  the  first  the  air  gas  mixture  was  drawn 
through  continuously  until  the  break  point  was  reached.  The 
results  obtained  in  this  way,  however,  did  not  give  the  time 
measure  of  the  value  of  a  canister  in  actual  use.  The  inter- 
mittent test  differs  only  in  that  the  flow  of  air-gas  mixture 
is  intermittent,  corresponding  to  regular  breathing.  Special 
valves  were  adapted  to  this  work. 

Canisters  must  also  be  tested  as  to  the  protection  they 
offer  against  smoke.  These  methods  are  discussed  in  Chapter 
XVIII. 

.  Man  Tests 

The  final  test  of  the  canister  is  always  carried  out  by  means 
of  the  so-called  ^'man  test."  Special  man-test  laboratories 
were  built  at  Washington,  Philadelphia  and  Long  Island. 
These  are  so  constructed  that,  if  necessary,  a  man  may  enter 
the  chamber  containing  the  gas  and  thus  test  the  efficiency  of 
the  completed  gas  mask.  In  most  cases,  however,  the  canister 
is  placed  inside  or  outside  the  gas  chamber  and  the  men 
breathe  through  the  canister,  detecting  the  break  point  by 
throat  and  lung  irritation. 

The  following  brief  description  of  the  man  test  laboratory 
at  the  American  University  will  give  a  good  idea  of  the  plan 
and  procedure.^ 

The  man  test  laboratory  is  a  one-story  building,  56  ft. 
in  length  and  25  ft.  in  width.  The  main  part  is  occupied  by 
three  gas  chambers,  laboratory  tables,  and  various  devices  for 
putting  up  and  controlling  gas  concentrations  in  the  chambers. 

small  part  at  one  end  is  used  as  an  office  and  storeroom. 

Good  ventilation  is  of  great  importance  in  a  laboratory 
of  this  nature.  This  is  secured  by  means  of  a  6  ft.  fan  con- 
nected to  suitable  ducts.  The  fan  is  mounted  on  a  heavy  frame- 
v/ork  outside  and  at  one  end  of  the  building.    The  fan  is  driven 


*  Taken  from  Fieldner  's  article  mentioned  above. 


264 


CHEMICAL  WARFARE 


at  a  speed  of  about  250  r.p.m.  by  a  10  h.p.  motor.  The  main 
duct  is  33  in.  square,  extending  to  all  parts  of  the  building. 
A  connection  is  also  made  to  a  small  hood  used  when  making 
chemical  analyses. 

The  gases,  fumes,  etc.,  drawn  out  by  the  fan,  are  forced 
up  and  out  of  a  stack  30  in.  in  diameter,  extending  upward 
55  ft.  above  the  ground  level. 

The  main  features  of  each  of  the  three  gas  chambers  are 
identical.     Auxiliary  pieces  of  apparatus  are  used  with  each 


Fig.  76. — Man  Test  Laboratory,  American  University. 


chamber,  the  type  of  apparatus  being  determined  by  the  char- 
acteristics of  the  gas  employed. 

Each  chamber  is  10  ft.  long,  8  ft.  wide  and  8^/2  ft.  high, 
having,  therefore,  a  capacity  of  680  cu.  ft.  or  19,257  liters.  The 
floor  is  concrete,  and  the  walls  and  ceiling  are  constructed  on 
a  framework  of  2  X  4  in.  scantling,  finished  on  the  outside 
with  wainscoting  and  on  the  inside  with  two  layers  of  Upson 
board  (laid  with  the  joints  lapped)  covered  with  a  %  in.  layer 
of  special  cement  plaster  laid  upon  expanded  metal  lath.  The 
interior  finish  is  completed  by  two  coats  of  acid-proof  white 


TESTING  ABSORBENTS  AND  GAS  MASKS 


265 


paint.  The  single  entrance  to  the  chamber  is  from  outside 
the  laboratory,  and  is  closed  by  two  doors,  with  a  36  X  40  in. 
lock  between  them.  These  doors  are  solid,  of  3-ply  construc- 
tion, 21/2  in.  thick,  with  refrigerator  handles,  which  may  be 
operated  from  either  inside  or  outside  the  chamber.  The  door 
jambs  are  lined  with  ^/^^  in.  heavy  rubber  tubing  to  secure  a 
tight  seal. 

At  the  end  of  the  chamber  opposite  the  doors,  a  pane  of 
Vi  in.  wire  plate  glass,  36  X  48  in.,  is  set  into  the  wall,  and 


FRONT  VIEW 

With  Standard  Nuvy  Canister 

and  Adapter  in  Place 


SIDE  VIEW 
With  Standard  U.S 
Canigter  in  Place 


Fig.  77. — Details  of  Canister  Holder. 


additional  illumination  may  be  secured  by  2  licadlights,  12  in. 
square,  set  into  the  ceiling  of  the  chamber  and  of  the  air-lock, 
respectively,  and  provided  with  200  watt  Mazda  lamps  and 
Holophane  reflectors.  Openings  into  the  chamber,  five  in 
number,  are  spaced  across  this  end  beneath  the  window  and 
9  in.  above  the  table  top. 

Fans  are  installed  for  keeping  the  concentration  uniform. 

Various  devices  have  been  installed  for  attaching  the 
canister  to  be  tested  (Fig.  77).  This  arrangement  allows 
the  canister  to  be  changed  at  will  without  any  necessity  for 
disturbing  the  concentration  of  gas  by  'entering  the  chamber. 


266  CHEMICAL  WARFARE 

Arrangements  for  removing  the  gas  from  the  chamber  con- 
sist of  a  small  ^'bleeder"  which  allows  a  continuous  escape 
of  small  amounts  and  a  large  blower  for  rapidly  exhausting 
the  entire  contents  of  the  chamber. 

Other  general  features  of  the  equipment  deal  with  the 
determination  of  the  physical  condition  surrounding  the  tests, 
often  a  matter  of  considerable  importance.  The  temperature 
of  the  gas  inside  the  chamber  is  easily  ascertained  by  means 
of  a  thermometer  suspended  inside  the  window  in  such  a  posi- 
tion as  to  be  read  from  the  outside.  The  relative  humidity 
of  the  mixture  of  air  and  gas  in  the  chamber  is  determined 
by  means  of  a  somewhat  modified  Regnault  dew  point  apparatus 
mounted  on  the  built-in  table. 


Pressure  Drop  and  Leak  Detecting  Apparatus 

Another  piece  of  apparatus  consists  of  a  combined  pressure 
drop  machine  and  leak  tester  (Fig.  78)  for  measuring  the  resist- 
ance of  canisters  and  testing  them  for  faulty  construction.  This  is 
mounted  on  a  small  table,  with  the  motor  and  air  pump  installed 
on  a  shelf  underneath.  The  resistance,  or  pressure  drop,  of 
canisters  is  measured  by  the  flow  meter  A  and  the  water  manom- 
eter B.  Air  is  drawn  through  the  canister  and  the  flow  meter 
A  at  the  rate  of  85  liters  per  min.,  the  flow  being  adjusted  by  the 
needle  valve.  The  pressure  drop  across  the  canister  is  read  on 
the  water  manometer  B,  one  end  of  which  is  connected  to  the 
suction  line,  the  other  open  to  the  air.  The  reading  is  generally 
made  in  inches,  correction  being  made  for  the  resistance  of  the 
connecting  hose  and  the  apparatus  itself. 

Canisters  are  tested  for  leaks  by  the  apparatus  shown  at  B 
in  Fig.  78.  The  canister  is  clamped  down  tightly  by  wing  nuts 
against  a  piece  of  heavy  i/4-in.  sheet  rubber  large  enough  to 
cover  completely  the  bottom  of  the  canister  and  prevent  any 
inflow  of  air  through  the  valve.  Suction  is  then  applied,  and  a 
leak  is  indicated  by  a  steady  flow  of  air  bubbles  through  the 
liquid  in  the  gas-washing  cylinder  E.  A  second  gas-washing 
cylinder,  empty,  is  inserted  in  the  line  between  E  and  the 
canister  as  a  trap  for  any  liquid  drawn  back  when  the  suction 


TESTING   ABSORBENTS  AND  GAS  MASKS 


267 


is  shut  off.    If  a  leak  is  shown,  it  can  be  located  by  applying  air 
pressure  to  the  canister  and  then  immersing  it  in  water. 


Fig.  78. — Apparatus  for  Determining  Pressure  Drop  and  for  Detecting  Leaks 

in  Canisters. 


Methods  of  Conducting  Tests 

Three  general  methods  of  conducting  man  tests  are  followed : 
(1)  Canisters  are  placed  in  the  brackets  outside  the  chamber 
or  fastened  to  the  wall  tubes  within  the  chamber.  The  subjects 
of  the  test  remain  outside  the  chamber,  and  the  facepieces  of  the 
masks  are  connected  directly  to  the  canisters,  in  the  first  case, 
and  to  the  wall  tubes  connecting  with  the  canisters,  in  the  second 
case.  The  concentration  is  established  and  the  time  noted.  Then 
the  men  put  on  the  masks  and  breathe  until  they  can  detect  the 
gas  coming  through  the  canisters.  Reading  matter  is  provided 
for  the  men  during  the  test  period.  When  gas  is  detected,  the 
time  is  again  noted  and  the  time  required  for  the  gas  to  penetrate 
the  canister  is  reported  as  the  ' '  time  to  break  down "  or  "  service 
time"  of  the  canister.  Ten  canisters  are  tested  at  one  time,  and 
the  average  of  the  results  for  the  10  canisters  is  taken  for  that 
type  of  canister.    Much  less  accurate  results  are  obtained  when 


268  CHEMICAL  WARFARE 

the  final  figure  is  based  on  a  small  number  of  canisters.  This  is 
largely  due  to  the  various  breathing  rates  and  sensitiveness  of 
different  men. 

(2)  The  canisters  are  placed  as  in  (1),  but  it  is  only  neces- 
sary to  know  if  they  will  give  perfect  protection  for  a  given 
length  of  time.  The  procedure  is  the  same  as  in  (1),  except  that 
the  test  is  arbitrarily  stopped  at  the  end  of  the  indicated  time, 
and  the  number  of  canisters  and  the  service  times  of  the  same 
noted. 

(3)  When  the  canisters  are  of  such  a  type  that  they  cannot 
be  properly  tested  as  in  (1),  or  when  it  is  desired  to  test  the 
penetrability  of  the  facepiece,  the  men  wear  the  complete  mask 
and  enter  the  chamber.  They  remain  until  gas  penetrates  the 
canister  or  the  facepiece,  as  the  case  may  be,  or  until  it  is  deter- 
mined that  the  desired  degree  of  protection  is  afforded.  The 
service  time  is  computed  as  in  (1). 

(4)  Maximum-breathing-rate  tests  are  made  either  by  men  in 
the  chamber  or  by  the  men  outside,  in  which  they  do  vigorous 
work  on  a  bicycle  ergometer.  In  this  test  the  average  man  will 
run  his  breathing  rate  up  to  60  or  70  liters  per  min. 

The  concentration  of  the  gas  is  followed  throughout  the  test 
by  aspirating  samples  and  analyzing  them. 

Type  of  Masks  Used.  In  the  future  the  1919  model  will  be 
used  for  all  tests.  In  general,  during  the  War,  the  following 
procedure  held,  although  variations  occurred  in  special  cases : 

When  men  entered  a  gas  chamber,  the  full  facepiece  was,  of 
course,  required.  The  type  of  facepiece  was  determined  by  the 
nature  of  the  gas.  If  the  gas  was  most  easily  detected  by  odor 
or  eye  irritation,  a  modified  Tissot  mask  was  used.  If  it  was 
most  easily  detected  by  throat  irritation,  a  mouth-breathing 
mask  was  employed. 

When  men  were  outside  the  chamber,  the  choice  was  made  in 
the  same  manner,  except  in  the  case  of  detection  of  the  gas  by 
throat  irritation.  In  this  case  the  mouthpiece  was  attached  to 
two  or  three  lengths  of  breathing  tubes  and  a  separate  noseclip 
was  used.  The  facepiece  was  not  needed  and  the  men  were 
much  more  comfortable  without  it. 

Disinfection  of  Masks.  Mouthpieces  are  disinfected  after 
use  by  first  holding  them  under  a  stream  of  running  water  and 


TESTING  ABSORBENTS  AND  GAS  MASKS  269 

brushing  out  thoroughly  with  a  test-tube  brush ;  then  the  latter  is 
dipped  into  a  2  per  cent  solution  of  lysol,  and  the  inner  parts  of 
the  mouthpiece  are  brushed  out  well ;  finally  the  mouthpiece  and 
exhaling  valve  are  dipped  bodily  into  the  lysol  solution  and 
allowed  to  dry  without  rinsing.  Tissot  masks  are  wiped  out  with 
a  cloth  moistened  in  alcohol,  followed  by  another  cloth  moistened 
in  2  per  cent  lysol  solution.  The  flexible  tubes  are  given  periodic 
rinsings  whh  95  per  cent  alcohol. 

Applicability  of  Man  Tests.  Man  tests  are  applicable  to 
all  gases  which  can  be  detected  by  the  subject  of  the  test  before 
he  breathes  a  dangerous  amount. 

The  man  test  laboratory  described  above  provides  facil- 
ities for  obtaining  information  concerning  the  efficiency  of 
canisters,  facepieces,  etc.,  within  very  short  periods  of  time, 
without  waiting  for  the  construction  of  special  apparatus 
required  for  machine  tests.  To  get  satisfactory  results  from 
machine  tests,  a  delicate  qualitative  chemical  test  for  the  gas  is 
essential.  Man  tests  can  be  made  when  such  a  qualitative  test 
is  not  known.  Further,  man  tests  can  be  made  with  higher  con- 
centrations of  some  gases  than  is  practicable  with  machines. 
Evolution  of  excessive  amounts  of  moisture  when  high  concentra- 
tions of  some  gases  are  used  causes  much  more  trouble  with 
machine  tests  than  with  man  tetsts. 

On  the  other  hand,  man  tests  are  adversely  affected  by  the 
varying  sensitiveness  and  lung  capacities  of  the  men,  and  the 
humidity  of  the  air-gas  mixture  is  not  subject  to  as  exact  control 
as  is  the  case  with  machine  tests. 


Field  Tests 

It  will  be  observed  that  all  of  the  above  tests  are  concerned 
only  with  the  efficiency  of  the  absorbent  and  its  packing  in  the 
canister.  No  attempt  was  made  to  determine  the  comfort  and 
general  **feel"  of  the  mask.  For  this  purpose  field  tests  were 
devised,  covering  periods  from  two  to  five  hours.  The  first  test 
was  a  five-hour  continuous  wearing  test.  It  was  assumed  that 
any  mask  which  could  be  worn  for  five  hours  without  developing 
any  mark-ed  features  of  discomfort  could,  if  the  occasion  de- 


270 


CHEMICAL  WARFARE 


manded  it,  be  worn  for  a  much  longer  period  of  time, 
test  follows: 


A  typical 


Gas- 


8 :  00  to    8 :  30  Instruction  and  adjustment  of  gas  mask. 

chamber  tests 

8 :  30  to    9 :  30  Games  involving  mental  and  physical  activity 

9 :  30  to  1 1 :  30  Cross-country  hike  with  suitable  periods  of  rest 

1 1 :  30  to  1 2 :  00  Tests  of  vision 

12 :  00  to  12 :  30  Games  to  test  mental  condition  of  subjects 

12 :  30  to    1 :  00  Gas-chamber  fit  test 


Fig.  79. — Hemispherical  Vision  Chart. 

Vision  was  tested  by  means  of  a  hemispherical  chart  (Fig. 
79).  This  chart  was  6  ft.  in  diameter  and  was  constructed  of 
heavy  paper  laid  over  a  wire  frame.  A  hinged  head  rest  was  pro- 
vided for  holding  the  subject's  head  firmly  in  position  with  the 


TESTING  ABSORBENTS  AND  GAS  MASKS  271 

center  directly  between  the  eyes.  The  subject  wearing  the  mask  took 
up  his  position,  and  with  one  eye  closed  at  a  time,  indicated  how 
far  along  the  meridian  of  longitude  he  could  see  with  the  other 
eye.  The  observer  sketched  in  the  limit  of  vision  by  outlining  the 
perimeter  of  the  roughly  circular  field  allowed  by  each  eyepiece. 
The  intersection  of  the  two  fields  gave  the  extent  of  binocular 
vision  possible  with  the  mask. 

Various  other  tests  were  also  used,  in  order  that  the  extent 
and  nature  of  the  vision  could  be  accurately  determined. 

Aside  from  the  problems  of  comfort,  protection,  vision  and 
other  important  features  of  gas  mask  efficiency,  the  question 
arose  as  to  whether  certain  designs  of  masks  or  canisters  were 
mechanically  able  to  withstand  the  rough  treatment  they  were 
certain  to  receive  in  actual  field  service.  A  test  was,  therefore, 
developed  to  simulate  such  service  as  transportation  of  masks 
from  base  depots  to  the  front,  carrying  of  supplies  and  munitions 
by  men  wearing  masks  in  the  ''alert"  position,  exposure  to  rain 
and  mud,  hasty  adjustment  of  masks  during  gas  alarms  and 
typical  mistreatment  of  masks  by  the  soldiers. 

All  these  tests  were  of  great  value  in  the  development  of  a 
good  gas  mask. 


CHAPTER  XV 
OTHER    DEFENSIVE    MEASURES 

Protective  Clothing 

Protective  clothing  was  an  additional  feature  of  the  general 
program  of  protection.  As  far  as  factory  protection  is  con- 
cerned, the  use  of  protective  garments  was  more  or  less  of  a 
temporary  expedient  and  they  were  abandoned  as  fast  as  auto- 
matic machinery  and  standard  practice  made  their  use  less 
necessary.  It  is  likewise  a  question  regarding  their  value  at  the 
front.  It  is  very  certain  that  the  garments  developed  needed  to 
be  made  lighter  and  more  comfortable  to  be  of  much  value  to 
the  fighting  unit. 

The  first  development  of  protective  clothing  was  along  the 
lines  of  factory  protection.  The  large  number  of  casualties  in 
connection  with  the  manufacture  of  mustard  gas  made  it  impera- 
tive that  the  workmen  be  protected  not  only  from  splashes  of  the 
liquid  mustard  gas,  but  also  from  its  vapors.  The  first  suit  de- 
veloped provided  protection  to  the  entire  body.  The  ordinary 
clothing  materials  and  even  rubberized  fabrics  offered  little 
protection  but  it  was  found  that  certain  oilcloths  were  practically 
impermeable  to  mustard  gas.  The  suit  was  a  single  garment, 
buttoning  in  the  back,  with  no  openings  in  the  front,  no  pockets 
and  with  tie-strings  at  wrists  and  ankles.  The  head  was  pro- 
tected by  means  of  an  aluminium  helmet,  supported  by  means 
of  a  head  band  resting  on  the  head  like  a  cap  and  slung  from 
the  inside  of  the  helmet;  this  permitted  slight  head  motions 
independent  of  the  helmet.  In  order  to  provide  cooling  and 
ventilating  and  pure  air  breathing,  the  suit  was  inflated  by 
pumping  a  considerable  volume  of  air  into  the  suit  through  a 
flexible  hose  long  enough  to  permit  considerable  freedom  of 
movement. 

272 


I 


OTHER  DEFENSIVE  MEASURES 


273 


This  suit  had  the  very  great  disadvantage  of  limiting  the 
range  of  motion  to  the  length  of  the  hose.  Because  of  this,  a 
Tissot  type  mask  was  used  in  place  of  the  helmet  and  hose  con- 
nections. The  hood  was  made  of  the  same  special  oilcloth  as  the 
suit,  enveloped  the  head  and  neck  and  extended  a  short  distance 
down  the  back  and  over  the  chest.  The  canister  was  slung  on 
the  left  hip  by  an  oilcloth  harness  and  was  kept  from  swinging 
by  an  oilcloth  belt  around  the  waist.     The  canister  was  much 


Fig.  80. — Impervious  Overall  Suit  for  Mustard  Gas. 

larger  than  the  standard  box  respirator,  had  a  much  longer  life 
with  lower  resistance  and  weighed  about  3.5  lbs. 

Another  type  of  impervious  overall  suit  was  developed  which 
protected  against  mustard  gas  for  over  100  minutes.  The 
material  was  a  cotton  sheeting  which  was  impregnated  with 
linseed  oil  containing  a  suitable  non-drying  material,  which  was 
thoroughly  oxidized  in  the  fabric.  These  suits  proved  to  be  very 
uncomfortable,  especially  in  warm  weather,  because  they  entirely 
prevented  the  escape  of  perspiration  from  the  body. 


274  CHEMICAL  WARFARE 

Semi-permeable  suits  were  then  prepared,  in  which  the 
cotton  sheeting  was  impregnated  or  coated  with  a  solution  of 
gelatin  and  glycerine.  The  fabric  was  then  *' tanned '*  to  render 
the  gelatin  insoluble  in  water.  Such  a  suit  is  valuable  for  factory 
wear,  but  the  impregnating  material  is  easily  leached  out  and 
the  suit  is  therefore  not  recommended  for  field  service. 

This  was  built  with  an  inside  layer  of  dry  cloth  together  with 
an  outside  layer  of  treated  cloth  to  afford  the  necessary  chemical 
protection  against  mustard  gas.  Work  of  fabrication  consisted 
in  treating  the  cloth  with  simplexene,  cutting  the  suits  to  design 
and  size,  and  sewing  them  together. 

Treatment  consisted  in  passing  the  fabric  through  a  dye 
machine,  then  through  the  wringer  rolls  where  the  excess  oil 
was  expressed.  The  inner  layer  of  dry  cloth  was  found  neces- 
sary, since  the  cloth  was  cut  as  soon  as  treated.  Simplexene  does 
not  attain  the  maximum  degree  of  *' tackiness '*  for  two  or  three 
days,  owing  to  the  presence  in  the  oil  of  a  small  amount  of 
volatile  spirits.  However,  by  allowing  the  cloth  to  air  for  48 
hours  before  cutting,  the  inner  lining  could  probably  be  dis- 
pensed with. 

The  fighting  suits  were  distributed  among  various  detach- 
ments using  mustard  gas  in  field  tests,  and  in  other  places  where 
protection  against  vapor  was  needed  and  where  field  conditions 
were  approximated.  The  tests  showed  that  the  suit  gave  satis- 
factory protection  for  considerable  periods  against  mustard  gas 
vapors.  No  other  suit,  equal  both  in  porosity  and  protection,  has 
yet  been  submitted,  although  samples  furnishing  better  pro- 
tection with  much  higher  resistance  have  been  examined.  The 
protection  of  the  simplexene  suit  is  about  30  minutes  against 
saturated  gas.  A  large  number  of  these  suits  were  made  and 
taken  abroad  for  field  tests  at  the  front. 

Protective  Gloves 

Protective  gloves  have  been  made  with  a  variety  of  impreg- 
nating agents.  The  one  which  was  selected  for  large  scale  pro- 
duction was  impregnated  with  a  solution  of  cellulose  nitrate 
because  of  the  availability  of  materials  and  the  protection  offered 
by  the  finished  product.     The  material  is  impregnated  after 


OTHER  DEFENSIVE  MEASURES 


275 


being  made  up.  The  one  finger  type  of  glove  is  used.  The  gloves 
are  placed  on  wooden  forms  and  dipped  into  the  impregnating 
solution.  After  draining  a  few  minutes,  the  gloves  are  turned 
upside  down  on  racks  and  run  through  a  drying  oven.  Finally 
they  are  removed  from  the  forms  and  conditioned  by  drying  at 
a  moderate  temperature  for  several  hours.  After  being  properly 
cured  they  are  fitted  with  two  straps  on  the  gauntlet  of  each 
glove.     They  should  offer  protection  to  chloropicrin   (standard 


I 


Fig.  81. — Coated  Gloves  for  Protection  against  Mustard  Gas. 


ethod  of  test)  for  30  minutes.    When  subjected  to  rough  work 
they  will  last  from  one  to  two  weeks. 

Protective  Ointments 

The  extensive  use  of  mustard  gas  on  the  field  caused  the  men 
to  be  exposed  to  low  concentrations  of  the  vapors  for  extended 
periods  of  time.  Since  it  did  not  seem  feasible  to  furnish  the 
men  with  special  fighting  suits,  which  would  protect  them  against 
these  vapors,  it  was  desirable  to  provide  protection  in  the  form 
of  an  ointment  which  could  be  applied  to  the  body.  In  order  to 
be  satisfactory  an  ointment  should  have  the  following  properties : 


276  CHEMICAL  WARFARE 

{a)  It  should  protect  against  saturated  mustard  gas  during 
the  longest  possible  exposure. 

(6)  Its  protective  action  should  last  as  long  as  possible  after 
the  application  of  the  ointment.  It  was  felt  that  the  ointment 
should  give  protection  for  24  hours  after  it  is  applied,  even  if 
the  body  is  perspiring  freely. 

(c)  The  material  should  not  be  easily  rubbed  off  under  the 
clothing. 

(d)  It  should  be  non-irritating  to  the  membranes  of  the  body. 

(e)  There  should  be  no  likelihood  of  toxic  after-effects  on 
long  use. 

(/)  It  should  be  of  a  good  consistency  under  a  fairly  wide 
temperature  range  and  give  a  good  coating  at  the  temperature  of 
the  body. 

(g)  Its  method  of  manufacture  should  be  simple  and  rapid, 
and  the  raw  materials  required  should  be  abundant. 

(h)  The  cost  should  not  be  excessive. 

An  extensive  study  of  this  question  was  made  both  in  the 
laboratories  and  on  the  field.  At  first  it  was  believed  that  suc- 
cessful results  could  be  obtained  by  the  use  of  such  ointments. 
Careful  investigation  showed,  however,  that  while  these  oint- 
ments really  did  protect  against  rather  high  concentrations  of 
vapor  for  short  times  of  exposure,  they  were  probably  not  so 
valuable  when  used  against  low  concentrations  over  an 
extended  period  of  time.  It  was  further  demonstrated  that 
the  protection  furnished  by  a  coating  of  linseed  oil  is  prac- 
tically equal  to  the  best  ointment  which  has  been  developed. 
About  150  ointments  were  prepared  and  tested.  These 
consisted  of  two  parts  or  components,  the  metallic  soap  or 
other  solid  material  and  the  oil  or  liquid  part  which  bound  and 
held  the  solid.  The  latter  is  called  the  base.  The  best  base  is 
lanolin,  containing  30  per  cent  of  water.  A  solution  of  wax  in 
olive  oil  was  next  best.  Of  the  metallic  soaps  the  oleates  and 
linoleates  are  better  than  the  stearates.  A  satisfactory  ointment 
has  the  following  composition : 

Zinc  oxide 40 

Linseed  oil  (raw) •.  20 

Lard 20 

Lanolin 20 


OTHER  DEFENSIVE  MEASURES  277 

A  modification  of  this  formula  is : 

Zinc  oxide 45 

Linseed  oil 30 

Lard 10 

Lanolin 15 

The  physical  properties  of  this  -ointment  are  very  good.  It 
forms  a  smooth,  even  coating  on  the  skin,  sticks  well  enough  not 
to  rub  off  easily  on  the  clothing  and  yet  is  not  sticky.  Its  con- 
sistency is  such  that  it  can  be  readily  pressed  from  an  ointment 
tube.  A.  E.  F.  reports  indicate  that -sag  paste  (zinc  stearate 
and  vegetable  oil)  is  as  satisfactory  as  any  of  the  preparations 
tried. 

The  great  difficulties  of  such  preparation  from  a  field  point 
of  view  are :  Extra  weight  to  be  carried  by  the  soldiers,  necessity 
for  keeping  in  tight  boxes  or  tubes,  thereby  adding  to  the  diffi- 
culty of  carrying,  and  finally,  the  difficulty  encountered  when 
applying  it  properly  to  the  body  in  the  field,  where  gas  con- 
taminated hands  may  cause  harm. 

The  paste  was  too  late  a  development  for  thorough  field  trial. 
It  was  used  just  enough  to  cause  severe  partisan  controversies 
between  its  advocates  and  those  opposed  to  it.  Unquestionably, 
it  proved  of  decided  value  in  preventing  mustard  gas  burns 
when  properly  applied.  There  are  many  authentic  cases  where 
men  alongside  each  other  were  similarly  gassed  except  as  to 
burns.  The  difference  in  burns  arose  from  the  use  or  non-use 
of  the  paste,  and  in  some  cases  of  poor  application.  Fries  is 
of  the  opinion  that  had  the  war  lasted  another  year  the  use  of 
pastes  would  have  become  universal  unless  some  thoroughly 
successful  substance  for  impregnating  the  uniform  or  under- 
clothing had  been  developed.  This  is  likewise  his  belief  for  the 
future. 

Protection  of  Animals 

Horse  Mask.  The  need  of  protection  for  animals  (horses 
and  dogs),  although  not  as  great  as  in  the  case  of  men,  was  of 
sufficient  importance  so  that  masks  and  boots  were  developed  for 
the  horse  and  a  mask  for.  the  dog. 


m 


278 


CHEMICAL   WARFARE 


The  German  horse  mask  was  the  first  produced.  It  was  of 
the  nose  bag  type,  enveloping  the  mouth  and  nose  of  the  animal. 
It  was  fitted  with  a  complicated  drawstring  and  with  snap  hooks 
fastening  it  to  the  harness.  The  interior  contains  a  plate  of  stiff 
material  to  prevent  the  collapse  of  the  bag.  The  mask  itself  was 
apparently  not  impregnated,  but  was  used  wet  or  with  a  filling 
of  wet  straw  or  rags  to  act  as  the  absorbent. 

The  French  had  two  types  of  horse  masks  impregnated  with 
a  glycerine-nickel  hydroxide  mixture.  One  type  had  a  closed 
bottom,  while  in  the  othe^*,  the  bottom  was  open. 

The  British  horse  mask  has  a  two-layer  flannelette  bag,  with 
a  canvas  mouth  pad  and  elastic  drawstring.    It  was  impregnated 


BACK  VIEW  SIDE  VIEW  BOX  FOR   RESPIRATOR 

Fig.  82. — German  Respirator  for  Horses. 


with  a  mixture  of  phenol,  formaldehyde,  ammonia,  canister  soda 
and  glycerine. 

The  first  type  of  American  horse  mask  was  modelled  after 
the  British  and  was  impregnated  with  the  Komplexene  mixture 
(hexamethylenetetramine,  glycerine,  nickel  sulfate  mixture). 
This  mask  had  too  high  a  resistance  and  caused  complete  exhaus- 
tion in  running  horses.  The  second  mask  was  made  of  a  large 
number  of  layers  of  very  open  cheesecloth.  It  consists  of  two 
bags,  impregnated  with  different  mixtures  (Komplexene  and 
Simplexene).  Horses  can  run  two  miles  with  this  mask  without 
showing  evidences  of  exhaustion. 

Dewey  gives  the  following  method  of  manufacture: 

The   chemical   employed  consisted   of   a   mixture   of  hexa- 


OTHER  DEFENSIVE  MEASURES 


279 


methylenetetramine  (to  give  protection  against  phosgene), 
nickel  sulfate  (to  protect  against  the  possible  use  of  hydrocyanic 
acid),  sodium  carbonate  and  glycerine.  This  solution  was  mixed 
in  a  heavy  steam  jacketed  mixing  kettle  with  heavy  geared 
stirrers.  The  mixture  was  conducted  by  pipes  to  the  impreg- 
nating apparatus  which  consisted  of  a  rotary  laundry  washing 
machine.  The  masks  were  treated  in  this  machine  for  15 
minutes,  and  then  placed  in  a  power  operated  wringer  and  the 


Fig.  83. — Horse  Mask — American  Type. 

solution  driven  off  to  a  given  weight.  Following  this  operation, 
they  were  suspended  on  wire  supports  and  conducted  through  a 
hot  air  drying  machine  and  dried  to  a  definite  weight.  378,000 
horse  masks  were  produced  at  the  rate  of  5,000  per  day. 

Theoretically,  horse  masks  and  horse  boots  are  very  valuable, 
— practically,  they  did  very  little  actual  good  in  the  field,  not 
that  they  would  not  protect  or  that  animals  would  not  wear  them. 
The  trouble  was  with  the  riders  and  drivers.  Gas  attacks, 
coming  usually  at  night,  made  adjustment  of  horse  masks  diffi- 
cult at  best,  while  in  the  confusion  of  bursting  shell  and  smoke, 


280  CHEMICAL  WARFARE 

the  drivers  absolutely  forgot  the  horse  masks  or  after  putting  on 
their  own  masks  feared  to  try  putting  masks  on  the  animals. 
This  last  was  natural  as  most  animals  fight  the  adjustment  of 
the  mask  and  in  so  doing  there  is  great  risk  that  the  man^s  mask 
may  be  torn  off  and  the  man  gassed.  In  the  future,  such  masks 
will  have  even  more  importance  than  in  the  past,  for  the  present 
methods  of  manufacture  of  mustard  gas  coupled  with  its  all- 
round  effectiveness  will  cause  a  use  of  it  ten-fold  greater  than  at 
any  time  in  the  World  War.  In  such  cases,  operations  will  neces- 
sarily be  frequently  carried  on  over  large  areas  thoroughly 
poisoned  with  mustard  gas.  Here  the  animals  will  be  masked 
and  booted  before  entering  the  gassed  area,  and  remain  so  until 
they  leave  it.  In  the  torn  and  broken  ground  around  the  front 
line  there  will  always  be  need  for  animal  transportation, — 
wagon,  cart  and  horse — as  in  such  places  it  is  far  better  in  nearly 
all  cases  than  motor  transport. 

Dog  Mask.  The  use  of  dogs  in  messenger  service  and  in 
Red  Cross  work,  in  which  gassed  areas  must  be  passed,  led  to  the 
designing  of  a  mask  to  give  the  animals  suitable  protection.  The 
same  materials  and  method  of  impregnation  were  used  as  in  the 
horse  mask.  With  eight  layers  of  cheesecloth,  adequate  protec- 
tion against  mustard  gas  was  secured  with  practically  no  pres- 
sure drop. 

The  eyepieces  were  made  of  thin  sheets  of  cellulose  acetate 
bound  around  the  edge  with  adhesive  tape  and  sewed  directly 
over  openings  cut  through  the  mask  fabric.  The  ear  pockets 
were  made  round  and  full  enough  to  fit  pointed  or  lop-eared 
animals.  The  mask  is  continued  to  form  a  wide  neck  band 
which  may  be  drawn  up  by  two  adjustable  straps.  It  is  made 
sufficiently  full  to  allow  a  free  movement  of  the  dog's  jaws  and 
yet  tight  enough  around  the  neck  to  avoid  the  possibility  of  being 
pawed  off.  The  dog  apparently  soon  became  accustomed  to 
wearing  the  mask. 

Horse  Boots.  The  increasing  amount  of  mustard  gas  used 
on  the  Western  front  made  it  seem  necessary  to  develop  some 
form  of  protection  for  the  horse's  hoof  and  fore-leg.  It  has 
been  found  that  mustard  gas  vapors  attack  the  fleshy  portion  of 
the  leg,  especially  around  the  coronary  band  and  causes  inflam- 
mation of  the  frog  of  the  foot.     The  problem  was  solved  by 


OTHER  DEFENSIVE  MEASURES 


281 


devising  a  special  lioof  pad  and  a  boot.  The  pad  was  made  of 
sheet  iron  imbedded  in  a  hoof  protector  (composition  rubber)  to 
which  the  shoe  is  applied.    The  shoe  just  overlaps  the  metal  plate 


Fig.  84. — Impervious  Boots  and  Pads  to  Protect  Horses'  Legs  and  Hoofs 
against  Mustard  Gas. 

on  the  inside  and  provides  a  solid  metal  surface  for  the  bottom 
of  the  foot.  Such  a  pad  not  only  offers  protection  against  gas 
but  against  shell  splinters,  barbed  wire,  etc.,  and  would  be  useful 
at  ail  times  on  the  front. 


282 


CHEMICAL  WARFARE 


The  boot  was  made  of  satin,  treated  so  as  to  be  impervious 
to  mustard  gas.  It  covers  all  of  the  foot  except  the  bottom  and 
extends  to  just  below  the  knee.  The  boot  is  held  in  contact  with 
the  hoof  by  a  sewed  cloth  strap,  which  passes  around  the  bottom 


Fig.  85. — Protective  Gas  Outfit — Gas  Mask,  Gas  Suit,  Gloves,  Boots,  Horse 
Mask,  Horse  Boots,  Horse  Pads. 

of  the  hoof  and  is  held  in  position  by  projections  extending  from 
the  spur  or  toe  clip.  Special  care  is  taken  to  insure  a  perfect 
joint  at  the  rear  of  the  boot  since  the  small  cavity  in  the  back  of 
the  hoof  is  one  of  the  most  sensitive  parts.  The  boot  is  wrapped 
about  one  and  a  half  times  around  the  leg  and  is  clipped  with  five 
loops  through  which  passes  a  %-inch  strap. 


OTHER  DEFENSIVE  MEASURES  283 

Dugout  Blankets.  Dugout  protection  is  intended  to  pre- 
vent entrance  of  any  gases,  lethal,  lachrymatory  or  irritant,  into 
the  enclosed  space.  This  has  been  most  efficiently  accomplished 
by  means  of  curtains  hung  upon  wooden  frames  and  fitting 
closely  against  all  edges  of  the  opening  to  be  closed.  These  cur- 
tains have  usually  been  of  heavy  material  and  have  generally 
been  spoken  of  as  dugout  blankets.  Since  they  were  designed  to 
exclude  all  toxic  gases,  they  had  to  be  devised  upon  general 
mechanical  principles  rather  than  upon  principles  of  chemical 
action  with  specific  gases.  Permeability  to  air  has  not  been 
considered  a  necessity,  it  being  held  that  sufficient  ventilation  is 
secured  by  means  of  the  air  entering  through  the  soil.  For  large 
dugouts  and  extended  use  large  air  filters  were  designed  to  draw 
pure  air  into  the  dugout  with  a  fan. 

The  qualities  aimed  at,  to  which  both  fabric  and  treatment 
should  contribute,  are  the  following: 

(o)   Impermeability  to  gas. 

(&)  Flexibility,  especially  at  low  temperatures. 

(c)  Non-inflammability. 

(d)  Freedom  from  stickiness  and  from  tendency  to  lose  material  by 
drainage  under  action  of  gravity. 

(e)  Mechanical  strength. 

(/)   Simplicity  of  manufacture  and  treatment. 
(g)  Low  cost. 

Army  blankets,  both  those  for  men  and  those  for  horses, 
proved  suitable  materials  for  curtains,  but  the  scarcity  of  wool 
made  it  desirable  to  select  an  all  cotton  fabric. 

A  large  number  of  oils  were  studied  as  impregnating  agents. 
The  most  satisfactory  mixture  consisted  of  85  per  cent  of  a  heavy 
steam  refined  cylinder  oil  and  15  per  cent  of  linseed  oil.  This  is 
taken  up  to  the  extent  of  about  300  per  cent  increase  in  weight 
of  the  blanket  during  impregnation.  It  becomes  oxidized  to  some 
extent  upon  the  surface  of  the  blanket,  which  becomes  less  oily 
than  the  soft,  central  core.  The  finished  blanket  possessed  the 
following  properties:  It  resists  penetration  of  400-600  p.p.m. 
of  chloropicrin  for  8  hours  (dugout  test)  and  mustard  gas  for 
100-400  minutes  (machine  test).  It  is  sufficiently  flexible  after 
standing  for  2  hours  at  18°  F.  to  unroll  of  its  own  weight,  and 


284  CHEMICAL   WARFARE 

may  be  unrolled  by  applying  a  slight  force  at  6°  F. ;  it  is  not 
ignited  by  lighted  matches  and  shows  but  little  loss  by  drainage. 
Two  types  of  machines  were  designed  for  impregnation,  one 
for  use  on  large  scale  behind  the  line,  and  a  field  apparatus  for 
use  at  the  front. 


I 


CHAPTER  XVI 
\  SCREENING    SMOKES 

The  intelligent  use  of  screening  smokes  in  modern  infantry 
tactics  offers  innumerable  advantages  through  concealment  and 
deception.  It  confers  upon  daylight  operations  many  of  the 
advantages  which  were  gained  by  conducting  operations  at  night 
with  few  of  the  disadvantages  of  the  latter. 

Smoke  screens  have  been  frequently  used  by  the  Navy  and 
by  Merchantmen ;  a  common  method  of  escape  was  to  shut  off  the 
air  from  the  fire  with  consequent  incomplete  combustion  of  the 
fuel,  thus  causing  a  cloud  of  dense  black  smoke.  This  is  often 
mentioned  in  the  blockade  runners  of  the  days  in  the  Civil  War, 
where  wood,  high  in  pitch  and  rosin,  was  freely  introduced  into 
the  furnaces,  in  order  that  they  might  escape  under  cover  of  this 
smoke. 

Early  in  the  present  war  it  was  found  that  black  smoke  had 
a  low  obscuring  power,  showed  frequent  rents  or  holes  and  were 
difficult  to  standardize.  Their  production  also  caused  a  con- 
siderable loss  in  the  speed  of  the  vessel.  They  therefore  fell  into 
disuse  except  for  emergency  purposes  and  today  the  standard 
smoke  for  screening  purposes  of  all  kinds  is,  without  exception, 
white.^  /" 

\>£boperties  of  Smoke  Cloud 

The  properties  most  desired  in  a  screening  smoke,  apart  from 
low  cost,  are:  (a)  Maximum  screening  power,  which  refers  to  the 
question  of  density,  i.e.,  a  relatively  thin  layer  must  completely 
obscure  any  object  behind  it,  and  (6)  Stability,  which  implies, 
among  other  things,  a  low  rate  of  settling  or  dissipation.  There 
is  little  reason  to  doubt  that,  within  limits,  the  smaller  the 

'  While  it  is  a  well  known  fact  that  black  smoke  is  not  as  efficient 
as  white  smoke  for  screening  purposes,  the  reason  for  this  fact  is  not  clear. 

28;" 


286  CHEMICAL  WARFARE 

particles  of  a  smoke  cloud,  the  more  completely  will  the  smoke 
possess  these  qualities.  The  screening  power  of  a  smoke  cloud 
depends  very  largely  upon  the  scattering  of  the  light  coming 
through  it,  and  by  analogy  with  those  peculiar  solutions  which 
we  call  colloidal,  we  should  expect  the  scattering  to  increase  as 
the  degree  of  subdivision  increases,  within  limits.  The  rate  of 
settling  is  unquestionably  an  inverse  function  of  the  size  of  the 
particles.  The  chief  aim,  therefore,  in  smoke  production  is  to 
attain  as  high  a  degree  of  subdivision  as  possible.  Methods  may 
be  classified  as  good  or  bad,  in  so  far  as  they  satisfy  or  fail  to 
satisfy  this  criterion. 

Raw  Materials  for  Smoke  Clouds 

It  is  obvious  that  only  gases  or  substances  capable  of  being 
brought  into  the  vapor  state  or  into  a  very  fine  state  of  sub- 
division can  be  used  for  producing  smoke  clouds.  The  reaction 
product,  of  which  the  smoke  particles  consist,  should  preferably 
be: 

{a)  Solid.  Otherwise  the  particles  will  tend  to  grow  in  size 
by  condensation  of  the  liquid  particles  present  in  the  cloud. 

(&)  Non-volatile.  If  volatile,  the  particles  will  disappear  by 
evaporation  as  the  cloud  is  diluted  by  air  currents.  Larger  par- 
ticles will  also  form  at  th.e  expense  of  the  smaller  ones. 

(c)  Non-deliquescent.  If  the  particles  are  deliquescent,  they 
will  tend  to  grow  by  condensation  of  water  vapor  upon  them. 

(d)  Stable  towards  the  usual  components  of  the  atmosphere, 
especially  moisture. 

"While  it  might  seem  that  it  would  be  difficult  to  fulfill  these 
conditions,  there  are  several  chemical  compounds  which  have 
been  successfully  used  as  smoke  producers.  This  does  not  mean 
that  they  fulfill  all  the  conditions,  but  they  represent  a  compro- 
mise between  the  various  requirements. 

\  Phosphorus.  One  of  the  earliest  materials  to  be  used  in 
smoke  clouds  was  phosphorus.  This  is  prepared  on  a  commercial 
scale  by  heating  phosphate  rock  (which  contains  calcium  phos- 
phate) with  sand  and  coke  in  an  electric  furnace.  Phosphorus 
occurs  in  two  forms,  white  and  red.  White  phospliorus,  which 
is  formed  when  the  vapor  of  the  substance  is  quickly  cooled,  is, 


I 


SCREENING^ SMOKES  287 


in  the  pure  state,  almost  colorless,  melts  at  44°  C,  boils  at  287° 
C,  is  readily  soluble  in  various  solvents,  and  is  luminous  in  the 
air,  at  the  same  time  emitting  fumes  (the  oxidation  product, 
phosphorus  pentoxide).  On  gentle  warming  in  the  air,  it  takes 
fire  and  burns  with  a  brightly  luminous  flame.  Red  phosphorus 
is  obtained  by  heating  white  phosphorus  out  of  contact  with  the 
air,  to  a  temperature  of  250°  to  300°  C.  Red  crusts  then  sep- 
arate out  from  the  colorless  liquid  phosphorus,  and  almost  the 
entire  amount  is  gradually  converted  into  a  red,  solid  mass.  If 
this  is  freed  by  suitable  solvents  from  the  small  amounts  of  un- 
changed white  phosphorus,  a  dark  red  powder  is  obtained,  which 
remains  unchanged  for  a  long  time  in  the  air,  does  not  appre- 
ciably dissolve  in  the  solvents  for  white  phosphorus,  does  not 
become  luminous,  and  can  be  heated  to  a  fairly  high  temperature 
without  igniting.  Further,  red  phosphorus  is  not  poisonous, 
while  white  phosphorus  is  highly  so. 

Either  form  burns  to  phosphorus  pentoxide,  which  is  con- 
verted by  the  moisture  of  the  air  to  phosphoric  acid, 

4P+5  02  =  2P205 
2  P2O5+6  H20  =  4  H3PO4 

Since  one  pound  of  phosphorus  takes  up  1.33  pounds  of 
oxygen  and  0.9  pound  of  water,  it  is  not  surprising  that 
phosphorus  is  one  of  the  best  smoke  producers  per  pound  of 
material.  Comparison  of  the  value  of  the  two  forms  for  shell 
purposes  have  invariably  pointed  to  the  superiority  of  the 
white  variety. 

In  addition  to  its  use  as  a  smoke  producer,  it  is  used  in 
incendiary  shell  and  in  tracer  bullets.  For  incendiary  purposes 
a  mixture  of  red  and  white  phosphorus  is  superior. 

Chlorosulfonic  Acid.  Chlorosulf onic  acid,  CISO2OH,  was 
first  employed  by  the  Germans  to  produce  white  clouds,  both 
on  land  and  on  sea.  For  this  purpose,  they  sprayed  or  dropped 
it  onto  quicklime,  the  reaction  between  it  and  the  lime  furnish- 
ing the  heat  necessary  for  volatilization,  though  in  this  way 
about  30  per  cent  of  the  acid  is  wasted. 

Chlorosulfonic  acid  is  obtained  from  sulfur  trioxide  and 
hydrogen  chloride,  which  combine  when  gently  heated : 

S03+HC1  =  C1S020H 


288 


CHEMICAL  WARFARE 


SCREENING  SMOKES  289 

On  a  commercial  scale,  hydrogen  chloride  is  passed  into 
20  per  cent  oleum,  until  saturation  is  reached.  This  is  heated 
in  a  nitric  acid  still,  when  the  chlorosulfonic  acid  distills  over 
between  150°-160°  C.  With  30  per  c6nt  oleum,  the  conversion 
factor  is  about  42  per  cent.  The  residue  in  the  still  is  about 
98  per  cent  sulfuric  acid. 

.  It  forms  a  colorless  liquid,  boiling  at  152°  C,  and  having 
a  density  of  1.7. 

Chlorosulfonic  acid  fumes  in  the  air,  because  reaction  with 
water  forms  sulfuric  acid  and  hydrochloric  acid. 

CISO2OH + H2O  =  H2SO4 + HCl 

This  material  was  not  used  by  the  United  States  since 
oleum  was  found  superior. 

Oleum.  Oleum  is  a  solution  of  20  to  30  per  cent  sulfur 
irioxide  (SO3)  in  concentrated  sulfuric  acid.  It  has  been  used 
by  the  Germans  to  produce  clouds  on  land  and  sea,  by  its 
contact  with  quicklime,  and  by  the  Americans  for  screening 
tanks  and  aeroplanes.  Sulfur  trioxide  has  been  found  to  be 
superior  as  a  shell  filling.  It  is  believed  that  the  smoke 
producing  power  of  oleum  is  due  solely  to  its  sulfur  trioxide 
content,  the  sulfuric  acid  itself  acting  only  as  a  solvent.  The 
rather  high  freezing  point  of  the  oleum  containing  high  per- 
centages of  sulfur  trioxide  is  a  disadvantage. 

Sulfur  Trioxide.  Sulfur  trioxide,  SO3,  is  a  colorless  mobile 
liquid,  which  boils  at  46°  C.  and  solidifies  to  a  transparent 
ice-like  mass,  melting  at  15°  C.  It  is  prepared  by  passing 
a  mixture  of  sulfur  dioxide  and  oxygen  over  finely  divided 
platinum  or  other  catalysts  at  a  temperature  between  400  and 
450°  C.  Sulfur  trioxide  can  only  be  used  as  a  filler  for  shell 
and  bombs,  and  is  probably  the  best  substitute  for  phosphorus. 

Tin  Tetrachloride.  Tin  tetrachloride,  SnCl4,  is  obtained 
by  the  action  of  chlorine  on  metallic  tin.  It  is  a  liquid,  boiling 
at  114°  C,  and  having  a  density  of  2.2.  It  fumes  in  the  air, 
because  it  hydrolyzes  to  stannic  hydroxide : 

SnCl4+4  H20  =  Sn(OH)4+4  HCl 

It  makes  a  better  and  more  irritating  smoke  for  shell  and 
and  grenades,  than  either  silicon  or  titanium  tetrachlorides. 


i 


290  CHEMICAL  WARFARE 

Since  there  is  practically  no  tin  in  this  country,  the  other 
tetrachlorides  were  developed  as  substitutes. 

Silicon  Tetrachlodie.  Silicon  tetrachloride,  SiCl^,  is  pre- 
pared from  silicon  or  from  impure  silicon  carbide  by  heating 
it  with  chlorine  in  an  electric  furnace.  The  raw  material 
(silicon  carbide)  is  a  by-product  in  the  manufacture  of  car- 
borundum. It  is  a  colorless  liquid,  boiling  at  about  58°  C,  and 
fumes  in  moist  air,  owing  to  hydrolysis : 

SiCU +4  H2O  =  Si(0H)4  +4  HCl 

It  is  not  very  valuable  in  shell,  though  it  is  more  effective  on 
moist,  cool  days  than  on  warm,  dry  ones.  Its  greatest  use 
is  found  in  the  smoke  cylinder,  combined  with  ammonia.  By 
the  action  of  the  moisture  of  the  air,  the  following  reaction 
takes  place: 

SiCl4+4  NH3+4  H20  =  Si(OH)4+4NH4Cl 

The  addition  of  a  lachrymator  gives  a  mixture  which  works 
well  in  hand  grenades  for  mopping  up  trenches. 
|\  Titanium  Tetrachloride.  Titanium  tetrachloride,  TiCl4;  is 
made  from  rutile,  TiOs,  by  mixing  with  30  per  cent  carbon  and 
heating  in  an  electric  furnace.  A  carbonitride  is  formed,  which 
is  said  to  have  the  composition  TigC^N^,  but  the  actual  com- 
position may  vary  from  this  to  the  carbide  TiC.  This  product 
is  heated  to  600-650°  C,  and  chlorine  passed  through,  giving 
the  tetrachloride.  It  is  a  colorless,  highly  refractive  liquid, 
which  boils  at  about  136°  C,  is  stable  in  dry  air  and  fumes 
in  moist  air.  The  best  smoke  is  produced  by  using  5  parts 
of  water  to  one  of  the  tetrachloride,  instead  of  the  theoretical 
4  parts  [which  would  form  Ti(0H)4].  Since  it  is  more  expen- 
sive to  manufacture  and  not  as  effective  as  silicon  or  tin 
tetrachloride,  it  is  used  only  as  an  emergency  material. 

Berger  Mixture.  One  of  the  most  important  smoke 
materials  was  the  zinc-containing  mixture,  which  was  used  in 
the  smoke  box,  the  smoke  candle,  certain  of  the  smoke  grenades 
and  in  various  forms  of  colored  smokes.  The  basis  of  this 
was  the  Berger  Mixture,  which  had  the  composition : 


SCREENING  SMOKES  291 

Zinc ...25 

Carbon  tetrachloride 50 

Zinc  oxide 20 

Kieselguhr 5 

Tliis  formula  produced  a  light  gray  carbon  smoke,  with  much 
carbon  in  the  residue.  In  this  mixture  the  zinc  and  carbon 
tetrachloride  react  to  form  zinc  chloride  and  carbon;  the 
kieselguhr  keeps  the  mixture  solid  by  absorbing  the  tetra- 
chloride, while  the  zinc  oxide  is  practically  useless,  as  its 
absorbing  power  is  small. 

In  order  to  accelerate  the  reaction  and  to  oxidize  the 
carbon,  thereby  changing  the  color  of  the  smoke  from  gray 
to  white,  an  oxidizing  agent  was  added.  Sodium  chlorate  was 
chosen  for  economic  reasons.  The  reaction  now  proved  to  be 
too  violent,  and  the  zinc  oxide  w^as  replaced  by  ammonium 
chloride.  This  cooled  the  smoke,  retarded  the  rate  of  burning 
and  added  to  the  density  of  the  smoke,  since  the  obscuring 
power  of  the  ammonium  chloride  is  high.  The  kieselguhr  was 
replaced  by  precipitated  magnesium  carbonate,  which  is  as 
good  an  absorbent,  gives  a  much  smoother  burning  mixture, 
and  also  adds  somewhat  to  the  density  of  the  smoke  by  virtue 
of  the  magnesium  mechanically  expelled.  The  mixture  then 
had  the  composition: 

Zinc 34.6 

Carbon  tetrachloride 40 . 8 

Sodium  chlorate 9.3 

Ammonium  chloride 7.0 

Magnesium  carbonate 8.3 

Size  of  Smoke  Particles 

In  the  problem  of  smoke  production,  the  size  of  the  particle 
is  of  great  importance.  Being  a  physical  quantity  it  can 
easily  be  correlated  with  such  physical  properties  as  settling, 
diffusion,  coagulation,  and  evaporation.  These  factors  are 
more  important  in  connection  with  toxic  smokes,  since  there 
the  penetration  factor  must  be  considered. 

Smoke  appears  to  consist  of  particles  of  all  sizes  from  10~^ 
cm.,  which  may  just  be  resolved  by  the  unaided  eye,  to  molec- 


292  CHEMICAL  WARFARE 

ular  dimensions,  10"^  cm.     The  larger  particles  settle  out  most 
rapidly  and  so  do  not  remain  long  in  suspension. 

Measurement 

Wells  and  Gerke  have  developed  a  form  of  ultra-microscope 
which  is  well  adapted  to  the  measurement  of  the  size  of  smoke 
particles.  The  ultra-microscope  is  a  Ioav  power  microscope 
using  intense  dark  ground  illumination  for  viewing  particles 
which  are  too  small  to  be  seen  by  transmitted  light.  They 
are  rendered  visible  in  this  way,  since  any  object,  no  matter 
how  small,  which  emits  enough  light  to  affect  the  retina  is 
visible,  provided  the  background  is  sufficiently  dark.  Thus 
stars  are  visible  at  night  and  dust  particles  are  easily  seen 
in  a  sunbeam  in  a  darkened  room.  The  larger  particles,  viewed 
in  this  way,  do  not  appear  larger  but  brighter.  The  apparent 
size  of  the  particles  is  determined  by  the  diffraction  pattern 
and  is  thus  dependent  only  on  the  optical  system  used  to  view 
them.  The  more  intense  the  incident  light,  the  brighter  the 
particles  appear.  In  the  ultra-microscope  described,  the  image 
of  an  intense  source,  such  as  a  concentrated  filament  lamp, 
or  an  arc,  is  focused  upon  the  particles  in  the  microscopic 
field,  but  the  axis  of  the  illuminating  beam,  instead  of  coin- 
ciding with  the  axis  of  the  microscope,  as  ordinarily  used,  is 
perpendicular  to  it.  The  beam  itself,  therefore,  never  enters 
the  microscope  at  all,  but  passes  under  the  objective  into  a 
blackened  chamber  where  it  is  absorbed.  The  field  of  the 
microscope  is  made  dark  by  placing  underneath  the  objective 
another  ** black  hole"  or  blackened  chamber  with  an  opening 
just  a  little  larger  than  the  field.^ 

The  method  used  for  measuring  the  velocity  consisted  in 
causing  the  particle  to  describe  a  definite  stroke  many  times 
in  succession  in  an  electric  field.  This  was  accomplished  by 
reversing  the  direction  of  the  field  with  a  rotating  commutator. 
The  convection  due  to  the  source  of  light  is  perpendicular 
to  this  motion  so  that  a  zigzag  line  is  obtained  (see  Fig.  88). 
The  amplitude  of  this  oscillation  is  an  accurate  measure  of 

^  This  ultra-microscope  is  described  in  J.  Am.  Chem.  Soc.  41,  312  (1919). 


SCREENING  SMOKES 


293 


m 


Fig.  87. — Ultramicroscope  for  Measuring  Size  of  Smcke  Particles, 


294 


CHEMICAL  WARFARE 


'«■! 

_^ 1 

Fig.  88. — Measurement  of  Smoke  Particles  by  Use  of  Ultramicroscope. 


I 


SCREENING  SMOKES  295 


the  distance  traversed  by  the  particle  under  the  electric  force 
for  a  definite  small  interval  of  time.  The  speed  of  the  rotating 
commutator  and  the  electric  field  are  both  susceptible  of  pre- 
cise measurement,  so  that  the  size  of  a  single  particle  is  pre- 
cisely determined. 

When  a  sample  of  smoke  is  viewed  in  the  ultra-microscope, 
it  appears  like  the  starry  heavens,  except  that  the  stars  are 
dancing  violently  about.  At  first  little  distinction  is  made 
between  the  particles,  as  there  seems  to  be  no  order  in  their 
motion,  but  soon  it  becomes  evident  that  the  brighter  particles 
are  more  sluggish  than  the  dim  ones.  This  is  due  to  the 
greater  mass  of  the  bright  particles,  for  they  are  larger.  The 
particles  are  all  moving  slowly  away  from  the  source  of  light 
and  eventually  diffuse  to  the  walls  of  the  cell. 

When  the  electric  field  is  turned  on,  about  one-third  of  the 
particles  immediately  migrate,  about  equally  in  both  direc- 
tions, to  the  two  electrodes.  If  the  field  is  reversed,  the  direc- 
tion of  migration  is  reversed  and  if  the  commutator  is  used 
the  particles  oscillate  regularly.  Sometimes  the  particles  may 
be  seen  to  combine  and  become  neutral,  in  which  case  oscilla- 
tion ceases. 

Concentration  of  Smoke 

In  measuring  the  concentration  of  smokes,  the  following 
terms  are  useful: 

Density.  The  density  of  a  smoke  is  defined  as  the  reciprocal 
of  the  thickness  of  the  smoke  layer  in  feet  necessary  to  obscure 
a  given  filament.  Thus  six  inches  of  a  smoke  of  density  2.0 
is  required  to  obscure  an  electric  light  filament,  whereas  one 
requiring  four  feet  would  have  a  density  of  4.  Another  way 
to  show  the  significance  of  this  definition  is  to  point  out  that 
if  a  definite  weight  of  a  stable  smoke  is  diluted  with  air  after 
it  is  formed,  the  product  of  the  volume  by  the  density  always 
remains  constant.  Any  marked  variation  in  this  rule  may  be 
taken  as  evidence  that  the  particles  of  smoke  are  undergoing 
a  change,  in  most  cases  due  to  evaporation. 

Total  Obscniring  Power.  The  volume  of  smoke  produced 
per  unit  weight  of  material  used  is  the  second  factor  in 
determining  the  value  of  a  smoke.    The  product  of  this  volume 


296  CHEMICAL  WARFARE 

per  unit  weight  by  the  density  of  the  smoke  is  the  real  measure 
of  effectiveness,  and  is  called  the  total  obscuring  power  (T. 
0.  P.)  of  the  smoke.  If  the  volume  is  expressed  in  cubic  feet 
per  pound  and  the  density  in  reciprocal  feet,  the  unit  of 
T.  0.  P.  is  square  feet  per  pound.  That  is,  it  expresses  the 
square  feet  of  a  smoke  wall,  thick  enough  to  completely 
obscure  a  light  filament  behind  it,  which  could  be  produced 
from  a  pound  of  the  reacting  substances.  The  total  obscuring 
power  of  some  typical  smokes  are  as  follows: 

Phosphorus 4600 

NH^CKNHs+HCl) 2500 

SnCl4+NH3-f  HaO 1590 

Berger  Mixture 1250 

SnCl4+NH3 900 

SO2+NH3 375 

In  all  measurements  of  density,  and  therefore  of  T.  0.  P., 
the  rate  of  burning  must  be  considered.  If  a  slow  burning  ma- 
terial be  compared  with  a  rapid  one,  the  former  will  not  reach 
its  true  maximum  density,  as  a  great  deal  of  the  smoke  may 
settle  out  during  the  time  of  burning.  Comparisons  of  T.  0.  P. 
are  significant  only  when  made  on  smoke  mixtures  of  the 
same  type  and  in  about  the  same  quantities. 

I     Measurement 

Two  methods  of  measuring  the  effectiveness  of  a  smoke 
cloud  have  been  devised,  one,  the  smoke  box,  which  measures 
the  obscuring  power  directly  by  observing  at  what  distance  a 
lamp  filament  is  obscured  by  intervening  smoke,  the  other,  the 
Tyndall  meter,  which  measures  the  intensity  of  the  scattering 
of  the  light. 

The  earliest  measurements  of  smoke  intensity  are  perhaps 
those  of  Ringelmann  {Revue  Techinquef  19,  286),  who  devised 
the  well  known  chart  of  that  name,  intended  mainly  for 
measuring  intensities  of  black  smoke  issuing  from  a  chimney 
at  a  distance.  The  first  measurements  for  military  purposes 
are  probably  due  to  Bertrand,  who  made  numerous  compara- 
tive studies  with  his  "salle  opacimetrique. "  This  was  a  room 
23  X  14  X  3.6  meters,  with  7  windows.     Two  doors,  one  pro- 


SCREENING  SMOKES 


:97 


vided  with  3  oculars  2  cm.  in  diameter,  gave  access  to  the 
room.  On  the  other  door,  opposite  the  first,  were  hung  several 
black  signs.  Six  pairs  of  columns  were  spaced  along  the  room 
at  measured  distances.  When  a  smoke  is  produced  in  the 
room,  the  black  paper  signs  first  become  invisible,  then  the 
door  itself,  and  finally  the  columns,  pair  by  pair.    They  reap- 


Macbeth  Illuminometer  / 

01     \     I 


Di=phram  D  C^Z^TZT 


Fig.  89.— Tyndall  Meter. 

pear  in  the  reverse  order,  and  as  a  measure  of  relative  opacity 
Bertrand  took  the  time  elapsing  between  the  detonation  and 
the  reappearance  of  the  farther  door. 

Smoke  Box.  The  smoke  box,  used  by  the  C.  W.  S.,  was 
constructed  of  wood  with  tight  joints,  and  had  a  moveable 
brass  rod  running  through  it  to  which  was  attached  a  small 
size  25-Watt  Mazda  lamp.     Tlie  density  of  each  smoke  intro- 


298 


CHEMICAL  WARFARE 


duced  in  the  box  is  determined  by  moving  this  lamp  back 
and  forth  until  a  point  is  reached  when  the  pattern  of  the 
filament  can  just  be  distinguished  by  the  observer  looking 
in  at  the  glass  window,  external  light  being  excluded  by  a 
black  cloth.     The  thickness  of  the  smoke  layer  between  the 


Wire  CraJle  held  in 


Paraf.'.n  sealing  joint 
between  tubes 


l' Adhesive  Tape 


Spring  Clamp  for  holding  / 
control  wire  past  ■~-~-.^_^/ 


Fig.  90.— Cottrell  Precipitation  Tube. 

glass  window  and  the  light  is  recorded  as  the  measure  of  the 
smoke  density.  For  field  tests,  a  larger  box,  6X8X8  feet 
(288  cubic  feet)  was  constructed.  The  observation  light  was 
moveable  in  a  line  connecting  the  mid-points  of  opposite  sides 
of  the  box.     To  insure  uniform  distribution  of  smoke,  a  fan 


SCREENING  SMOKES  299 

with  18-inch  blade  revolved  at  any  desired  speed  between 
60  and  250  r.p.m.  With  this,  results  are  obtained  indicating 
both  the  original  density  and  its  stability. 

Tyndall  Meter.  The  Tyndall  meter  was  first  devised  for 
studying  smokes  and  mists.  Tolman  and  Vliet  adapted  it  to 
Chemical  Warfare  purposes,  and  used  it  in  studying  the 
properties  of  smokes. 

The  apparatus  (Fig.  89)  consists  eventually  of  an  electric 
light  bulb,  a  condensing  lens  giving  a  beam  of  parallel  light 
which  passes  through  the  diaphragm,  and  a  Macbeth  illuminom- 
eter  for  measuring  the  strength  of  the  Tyndall  beam.  In 
case  the  material  is  a  liquid  suspension  or  solution,  it  is  intro- 
duced into  a  cylindrical  glass  tube,  while  smokes  and  mists 
are  premixed  directly  through  the  apparatus.  The  long  closed 
tubes  are  provided,  respectively,  for  absorbing  the  beam  after 
it  has  passed  through  the  disperse  system  and  for  giving  a 
dark  background  for  observing  the  Tyndall  beam.  Methods 
of  standardization  are  given  in  the  Journal  of  the  American 
Chemical  Society^  41,  299. 

A  third  method  for  analyzing  smokes  consists  in  the  use  of  an 
electrical  precipitator.  This  apparatus  consists  essentially  of 
a  modified  Cottrell  Precipitator,  with  a  central  wire  as  cathode 
surrounded  by  a  cylindrical  foil  as  anode  (Fig.  90).  The 
smoke  to  be  analyzed  is  drawn  through  the  apparatus  at  a  known 
rate,  and  the  particles  of  smoke  precipitated  on  the  foil  by  means 
of  a  high  voltage,  direct  current.  The  determination  of  concen- 
tration is  made  by  weighing  the  foil  before  and  after  precipita- 
tion. 


s^ 


Apparatus   for   Smoke   Production 
Smoke  Box 


The  smoke  box  was  developed  for  the  Navy  for  use  when  it 
was  desirable  to  have  the  smoke  screen  generated  away  from  the 
ship.  (The  smoke  funnel,  described  later,  was  operated  on  board 
ship).  The  float  consists  of  an  iron  container  (holding  the 
smoke  mixture)  surrounded  by  an  iron  float  to  support  the 
apparatus  when  it  is  thrown  into  the  water  (Fig.  91).  The 
iron   container   consists    of   a   cylinder   22    inches   high   and 


300 


CHEMICAL   WARFARE 


10  inches  in  diameter.  One-inch  holes  are  bored  II/2  inches 
from  the  top  of  this  cylinder,  from  which  the  smoke  is  emitted. 
The  iron  float  is  about  2  feet  in  diameter  and  8  inches  deep. 


Fig.  91. — Navy  Smoke  Box. 


Fig.  92. — Navy  Smoke  Box  in  Action. 


This  box  holds  appi-oximately  100  pounds  of  smoke  mixture,  and 
is  so  constructed  that  it  will  float  one  hour.  When  ignited,  the 
mixture  burns  9  to  9i/>  minutes.     The  smoke  produced  has  a 


SCREENING  SMOKES 


301 


T.  0.  P.  of  about  1900.    Fig.  92  shows  the  Navy  Smoke  Box 
in  action. 

Smoke  Candle 

Smoke  candles  are  used  for  producing  a  cloud  of  smoke  for 
screening  purposes  in  or  behind  the  lines.  They  are  made  by 
l)aeking  about  three  pounds  of  the  modified  Berger  Mixture  in  a 
container  (Fig.  93)   (galvanized  can  514  inches  by  3%  inches) 


Fig.  93.— B.  M.  Smoke  Candle. 


and  are  lighted  by  means  of  the  match  head  type  of  ignition. 
Smoke  is  given  off  at  a  uniform  rate  for  about  4  minutes,  form- 
ing a  dense,  fog-like  cloud  which  hangs  low  (Fig.  94).  This 
smoke  is  absolutely  harmless,  and  can  be  breathed  without  dis- 
comfort. The  obscuring  power  is  high  and,  with  a  favorable 
wind,  a  small  number  of  the  candles  will  produce  a  screen 
sufficiently  dense  to  allow  operations  to  be  carried  out  unseen  by 
the  enemy. 


302 


CHEMICAL  WARFARE 


Smoke  Grenade 

The  smoke  grenade  is  also  designed  for  use  in  trench  and 
field  warfare,  where  it  is  desired  to  produce  a  dense  smoke  screen. 
It  is  made  by  packing  340  grams  of  the  standard  smoke  mixture 
in  an  ordinary  light  metal  gas  grenade.  Around  the  top  of  the 
grenade  are  vents  closed  by  a  zinc  strip.  The  ignition  is  caused 
by  the  standard  bouchon  when  the  grenade  is  thrown.    The  heat 


Fig.  94.— Smoke  Cloud  from  B.  M.  Candle. 


of  the  reaction  burns  through  the  zinc  strip  and  a  dense  cloud  of 
smoke  is  evolved  for  45  seconds. 

Stannic  chloride  has  also  been  used  extensively  in  hand 
grenades,  as  it  gives  a  very  disagreeable  cloud  of  smoke  upon 
detonation.  Due  to  the  high  prices  and  urgent  need  of  tin  for 
other  purposes,  silicon  tetrachloride  was  substituted  for  tin  tetra- 
chloride towards  the  close  of  the  war.  A  mixture  of  silicon 
tetrachloride  and  chloropicrin  was  also  used.  This  not  only  gives 
a  very  good  smoke  cloud,  but  combines  with  it  the  toxic  proper- 
ties of  the  chloropicrin  cloud. 

The  method  of  firing  the  smoke  grenade  is  the  same  as  that 
of  any  grenade  using  the  same  type  of  bouchon.     Usually  the 


SCREENING  SMOKES 


303 


grenade  is  grasped  in  the  hand  for  throwing  in  such  a  manner 
that  the  handle  of  the  bouchon  is  under  the  fingers.  The  safety 
clip  is  pulled  out  with  the  other  hand  and  the  grenade  is  thrown 
with  an  overhand  motion.  IVhen  the  grenade  leaves  the  hand, 
the  handle  of  the  bouchon  flies  off,  allowing  the  trigger  to  hit  the 
cap  which  ignites  the  fuse. 

The  white  phosphorus  combined  hand  and  rifle  grenade  be- 
came the  standard  smoke  grenade  by  the  end  of  the  war.  Stan- 
nic chloride  was  used  to  clear  out  dugouts,  but  not  as  a  smoke 
producer. 


\ 


Stokes'  Smoke  Shell 


The  Stokes'  smoke  shell  was  perfected  to  furnish  a  means  of 
maintaining  the  best  possible  smoke  screen  at  long  ranges  by 


Fig.  95.— Stokes'  Smoke  Shell. 


means  of  an  easily  portable  gun.  The  3-inch  Stokes  shell,  as 
adapted  for  combustion  smokes,  weighs  about  13  pounds  and 
contains  about  4  pounds  of  standard  smoke  mixture.    This  shell 


304 


CHEMICAL  WARFARE 


is  designed  to  produce  a  continuous  screen  over  a  period  of  3  to 
4  minutes. 

Livens  Smoke  Drum 

The  Livens  smoke  drum  was  designed  for  use  with  the  8-inch 
Livens  projector,   so   as   to   produce   a   smoke   screen   of  large 


Fig.  96. — Livens  Smoke  Bomb. 


volume  and  long  duration  at  long  ranges.  The  drum,  as  adapted 
for  combustion  smokes,  weighs  17.5  pounds  empty  and  49  pounds 
loaded.  The  smoke-gas  mixture  was  specially  adapted  for  use  in 
the  Livens  drum. 

Smoke  mixtures  in  Livens  were  never  used  to  any  consider- 
able extent  in  the  war  and  it  is  questionable  if  they  ever  will  be. 
A  Livens  can  usually  only  be  fired  once  before  resetting,  hence 
Stokes  mortars  are  used  whenever  possible. 


SCREENING  SMOKES 


305 


Smoke  Funnel 

The  smoke  funnel  was  developed  for  the  production  of  a 
white  smoke  cloud  fi'om  the  stern  of  a  vessel.  The  smoke  pro- 
ducing materials  are  liquid  ammonia  and  silicon  tetrachloride, 
with  carbon  dioxide  as  a  compressing  medium.  This  is  the  most 
satisfactory   compressing   medium,    because:    (1)    The   silicon 


:z--:^^::^t^i^ 


■i^-  -^ . 


Fig.  97. — Navy  Smoke  Funnel. 


tetrachloride  is  forced  out  at  nearly  constant  pressure.  (2)  The 
carbon  dioxide  is  easily  compressed  to  a  liquid  and  can  be 
handled  in  this  form.  Further,  it  has  a  vapor  pressure  of  800 
pounds  at  60°  F.,  and  a  cylinder  can  be  nearly  emptied  without 
loss  in  efficiency.  (3)  Carbon  dioxide  is  sufficiently  soluble  in 
silicon  tetrachloride  to  cause  the  latter  to  effervesce  and  thus 
materially  aid  in  its  evaporation  on  spraying.  (4)  Liquid 
carbon  dioxide,  behaving  in  a  manner  similar  to  liquid  ammonia, 
affords  a  means  for  the  silicon  tetrachloride  to  ''keep  pace''  with 
the  ammonia,  under  changes  in  temperature,  and  thus  ensures  a 
more  nearly  neutral,  and  therefore  the  most  effective,  smoke. 
The  smoke  funnel  proper  consists  of  an  open  end  cylinder, 


306  CHEMICAL  WARFARE 

about  2  feet  in  diameter  and  7  feet  long,  mounted  in  a  horizontal 
position  on  an  angle  iron  frame.  At  one  end  is  an  18-inch  fan 
securely  fastened  to  the  cross  supports.  This  fan  is  operated 
by  hand,  through  gears  giving  a  ratio  of  about  30  to  1.  The 
silicon  tetrachloride  enters  the  cylinder  through  a  pipe,  which 
terminates  in  four  spray  nozzles,  while  the  ammonia  enters 
through  a  single  nozzle.  The  air  forced  into  the  funnel  serves 
to  hydrolyze  the  silicon  tetrachloride  and  mixes  the  vapors.  The 
resulting  reaction  evolves  a  dense  white  cloud  of  very  large 
volume   and  high   obscuring  power.      One  set   of   cylinders   is 


Fig.  98. — Navy  Smoke  Funnel  in  Operation. 

capable  of  maintaining  this  cloud  for  over  30  minutes.  Under 
normal  conditions  the  discharge  is  at  the  rate  of  2  pounds 
of  silicon  tetrachloride  to  1  pound  of  ammonia.  To  stop  the 
smoke,  the  silicon  tetrachloride  is  closed  first,  the  ammonia 
allowed  to  run  about  half  a  minute,  and  the  fan  is  shut  off  last. 


Smoke  Knapsack     n 

The  smoke  knapsack  furnishes  a  portable  apparatus  for  smoke 
production.  The  gross  weight  is  about  70  pounds;  when  in 
operation  it  gives  a  dense  white  smoke  for  about  15  minutes. 
The  operation  may  be  intermittent  or  continuous  and  the  quan- 
tity of  smoke  is  sufficient  to  completely  hide  one  platoon  of  men 


SCREENING     SMOKES  307 

in  skirmish  formation  with  a  5-mile  per  hour  enfilade  wind. 
The  apparatus  consists  of  two  steel  tanks  about  26  inches  in 
height  and  6  inches  in  diameter.  From  the  side  of  each  tank, 
but  near  the  bottom,  extends  a  short  pipe  on  which  is  placed  a 
suitable  valve.  A  flexible  armored  hose  connects  the  valve  to  a 
short  length  of  pipe  which  is  equipped  with  spray  nozzle.  The 
cylinders  are  charged  with  silicon  tetrachloride  and  ammonia 
under  pressure.  The  valves  may  be  operated  with  the  left  hand, 
while  the  sprayer  apparatus  is  held  in  the  right.  The  release 
buckles  are  within  easy  reach  of  both  hands. 


Shell       V 


While  many  special  devices  have  been  developed  by  means 
of  which  the  gas  troops  and  infantry  are  able  to  set  up  smoke 
clouds  on  short  notice,  the  smoke  shell,  fired  by  the  artillery, 
always  played  an  important  part  in  this  work.  In  the  same  way 
that  a  large  number  of  the  poison  gases  were  adapted  to  artillery 
use,  so  were  most  of  the  smoke  producing  substances. 

As  a  filler  for  smoke  shell,  phosphorus  easily  ranks  first,  and 
is  approached  only  by  sulfur  trioxide  in  very  humid  weather. 
A  rough  approximation  to  the  relative  values  of  some  of  its  rivals 
is  given  in  the  following  table: 


White  phosphorus 100 

Sulfur  trioxide 60-75 

Stannic  chloride 40 

Titanium  chloride 25-35 

Arsenic  chloride 10 


^P  Comparison  of  the  value  of  different  forms  of  phosphorus 
for  shell  purposes  has  invariably  pointed  to  the  superiority  of 
the  white  variety.  Mixtures  of  white  and  red  (2  to  1)  have  also 
proved  effective. 

A  complete  barrage  over  a  front  of  200  yards  can  be  estab- 
lished in  from  40  seconds  to  1  minute  and  maintained  by  firing 
a  salvo  followed  by  battery  fire  of  3  seconds.  Four  4.5-inch  how- 
itzers could  maintain  an  effective  barrage  over  a  front  of  1000 
yards.  The  influence  of  sunshine  is  very  marked,  as  in  moist- 
cool  weather  one  shell  every  15  seconds  is  sufficient. 


308 


CHEMICAL   WARFARE 


SCREENING  SMOKES  309 


I 


Screening  Tanks 

Tests  have  demonstrated  (see  Fig.  99)  that  successful  smoke 
screens  for  tanks  may  be  produced  by  spraying  oleum  into  the 
exhaust.  On  a  7-ton  tank  of  the  Renault  type  (40  H.  P.)  110  cc. 
per  minute  produced  a  large  volume  of  smoke,  which  had 
excellent  covering  power,  and  which  could  be  made  intermittent 
or  continuous  at  will. 

The  same  method  may  be  applied  to  aeroplanes,  and  to  ships. 
It  is  calculated  that  a  cylinder  containing  300  pounds  of  20 
per  cent  oleum  will  maintain  a  smoke  screen  on  a  ship  for  a 
period  of  15  minutes,  if  oleum  is  used  at  the  rate  of  23.6  pounds 
per  minute.  Since  the  cylinders  may  be  arranged  in  batteries, 
the  screen  may  be  continued  for  any  period  of  time.  The  Tank 
Corps  rather  favor  phosphorus  rifle  grenades  for  producing  a 
smoke  screen  at  a  distance  from  the  tank. 

Purpose  of  Smoke  Screen 

Smoke  screens  may  be  employed  with  one  or  more  of  the  fol- 
lowing objects  in  view : 

I  (1)  To  mask  known  enemy  observation  posts  and  machine 
gun  nests ;  to  conceal  the  front  and  flanks  of  attacking  troops, 
concentration  of  guns  and  tanks,  roads  and  concentration  points ; 
to  blind  the  flashes  of  batteries  in  action  and  to  hamper  aerial 
bservations. 

(2)  As  a  feint  to  draw  the  enemy's  attention  to  a  front  on 
hich  no  attack  is  being  made,  so  as  to  hold  his  troops  to  their 

trenches,  or  to  induce  him  to  expend  ammunition  needlessly  and 
to  put  down  a  barrage  in  the  wrong  place. 

(3)  To  simulate  gas  and  force  the  enemy  to  wear  his  mask. 
Gas  should  occasionally  be  mixed  with  smoke,  to  impress  upon 
him  the  belief  that  it  is  never  safe  to  remain  in  a  smoke  cloud 
without  wearing  his  mask. 

(4)  In  rolling  or  mountainous  country,  to  fill  valleys  with 
smoke  and  thereby  conceal  the  advance  from  all  observation,  in- 
cluding aerial. 

(5)  To  cover  the  construction  of  bridges,  trenches,  etc.,  in 
the  face  of  the  enemy. 


310  CHEMICAL  WARFARE 


The  Tactical  Value  op  Smoke 


> 


The  pall  of  smoke  that  hung  over  every  battlefield  of  the 
Civil  War  made  a  profound  impression  upon  Fries  when, 
as  a  boy,  he  first  read  of  those  battles.  However,,  prac- 
tically every  reference  made  to  smoke  treated  it  as  a  nuisance. 
It  obscured  the  field  of  vision  and  interfered  with  troop  move- 
ments as  well  as  with  the  aiming  and  firing  of  rifles  and  cannon, 
though  due  to  their  short  range  this  was  not  so  serious  as  it  would 
be  nowadays.  Nevertheless  so  deeply  was  this  interference  appre- 
ciated that  the  most  earnest  efforts  were  made  to  discover  a 
smokeless  powder.  This,  as  the  world  well  knows,  was  developed 
with  great  efficiency  during  the  latter  part  of  the  nineteenth 
century.  With  the  development  of  the  smokeless  powders  came 
also  a  better  understanding  of  the  action  of  powder,  whereby  the 
velocity  of  projectiles,  and  consequently  the  range  and  accuracy, 
were  greatly  increased.  This  increased  range  and  accuracy  of 
guns  forced  a  consideration  of  protection, — and  concealment  is 
one  form  of  protection. 

The  Navy  would  appear  to  have  been  the  first  branch  of 
the  American  forces  to  realize  how  valuable  a  smoke  screen 
may  be.  Thus  Fries,  in  August,  1913,  had  the  interesting 
experience  of  witnessing  a  week's  maneuvers  at  the  eastern 
entrance  to  Long  Island  Sound  between  the  Navy  and  the  Coast 
Artillery.  During  that  week  the  Navy  carried  out  extensive 
experiments  with  smoke  screens  both  by  day  and  by  night.  The 
smoke  in  all  cases  was  generated  by  smothering  the  fires  on 
destroyers  or  other  ships,  thus  causing  dense  clouds  of  black 
smoke  to  be  given  out  from  the  funnels. 

After  the  World  War  had  been  in  progress  some  time  and 
particularly  about  the  time  the  United  States  entered  it,  a 
determined  search  was  begun  for  more  efficient  smokes  and  more 
efficient  smoke  producers. 

In  the  Navy,  smoke  screens  were  expected  to  be  established 
by  small  craft  behind  which  larger  vessels  could  maneuver  for 
position  and  range.  These  screens  were  also  established  for  the 
purpose  of  cutting  off  the  view  of  enemy  submarines  or  other 
vessels,  thus  allowing  merchant  ships  or  even  warships  when 
injured  or  outclassed  to  escape. 


b 


SCREENING  SMOKES  311 


The  Army  was  mucli  slower  to  appreciate  the  value  of  smoke. 
In  fact,  apparently  no  army  really  realized  the  value  of  a  smoke 
screen  until  after  gas  warfare  became  an  accomplished  fact.  As 
is  well  known,  the  evaporation  of  the  large  quantity  of  liquid 
used  in  wave  attacks  caused  a  cloud  of  condensed  moisture.  This 
is  what  gave  rise  to  the  designation  "cloud  attack.*' 

English  regulations  for  defense  against  gas  in  the  early  days 
called  for  every  man  and  animal  to  stand  fast  upon  the  approach 
of  a  gas  cloud  and  remain  quiet  until  the  cloud  had  passed. 
Thus  casualties  were  reduced  to  a  minimum  and  the  English 
were  fresh  to  receive  the  attack  that  was  frequently  launched 
immediately  after  the  cloud  had  passed.  The  Germans  finally 
thought  of  the  plan  of  sending  over  a  fake  gas  attack.  In  tTiat 
way  they  simply  produced  a  smoke  cloud  that  looked  like  a  gas 
attack.  Naturally  the  English  stood  fast  as  before.  The  Ger- 
mans attacking  in  the  fake  cloud  naturally  caught  the  British 
at"  a  complete  disadvantage  with  consequent  disastrous  results 
to  the  latter. 

But  that  was  a  game  at  which  two  could  play.  About  this 
time  the  value  of  white  phosphorus  for  producing  a  smoke  screen 
was  taken  up  by  the  British  and  large  numbers  of  4-inch  Stokes 
mortar  shells  were  filled  for  that  purpose.  All  armies  then 
began  to  experiment  with  smoke-producing  materials.  Most  of 
these  were  liquid.  Of  them  all,  as  has  been  stated  before,  white 
phosphorus,  a  solid,  proved  the  best.  Toward  the  close  of  the 
war  these  smoke  screens  began  to  be  used  to  a  considerable  extent 
for  the  purposes  given  above.  No  one  who  has  engaged  in  target 
practice  and  encountered  a  fog,  or  who  has  hunted  ducks  and 
geese  in  a  fog  needs  to  be  told  of  the  difficulty  of  hitting  an  object 
he  cannot  see. 

The  First  Gas  Regiment  proved  its  worth  and  won  everlasting 
glory  by  using  the  Stokes'  mortars  of  the  British  with  their 
phosphorus  bombs  for  attacking  machine  gun  nests.  The  white 
phosphorus  in  that  case  had  a  double  effect.  It  made  a  perfect 
smoke  screen,  thereby  making  the  German  machine  gun  shots 
simply  shots  in  the  dark,  while  at  the  same  time  the  burning 
phosphorus  forced  the  gunners  to  abandon  their  guns  and  sur- 
render. Thus  phosphorus  played  and  will  play  in  the  future 
the  double  role  of  forming  a  defensive  screen  and  of  viciously 


312  CHEMICAL  WARFARE 

attacking  enemy  troops.  This  phosphorus,  which  catches  fire 
spontaneously,  burns  wet  or  dry,  total  immersion  m  water  alone 
sufficing  to  put  it  out.  This  means  of  extinguishing  the  flames 
being  almost  totally  absent  on  the  battlefield,  it  can  be  truthfully 
said  that  burning  phosphorus  is  unquenchable.  The  burns  are 
severe  and  difficult  to  heal.  For  these  reasons  white  phosphorus 
will  be  used  in  enormous  quantities  in  any  future  war. 

All  armies  have  begun  to  realize  this  value  of  smoke.  In  the 
future  it  will  be  the  infantryman's  defense  against  all  forms  of 
weapons  and  it  will  be  used  on  every  field  of  battle,  by  every  arm 
of  the  service  and  at  all  times,  day  or  night.  It  is  even  more 
effective  in  shutting  out  the  light  from  searchlights,  star  bombs 
and  similar  illuminants  for  use  in  night  attacks  than  it  is  in 
daylight.  With  this  straight  use  of  smoke  for  protection  will  go 
its  use  along  with  poisonous  gases.  Every  smoke  cloud  will  be 
poisonous  or  non-poisonous  at  the  will  of  the  one  producing  the 
cloud,  and  this  will  be  true  whether  it  is  produced  from  artillery 
shell,  mortar  bombs,  hand  grenades,  smoke  candles  or  other 
apparatus.  Thus  smoke  and  gas  together  will  afford  a  field  for 
the  exercise  of  ingenuity  greater  than  that  of  all  other  forms  of 
warfare.  The  only  limitation  to  the  use  of  smoke  and  gas  will 
be  the  lack  of  vision  of  commanders  and  the  ignorance  of  armies. 

Proper  recognition  and  aid  given  to  chemical  warfare 
development  and  instruction  in  peace  are  the  only  methods  of 
overcoming  these  limitations.  In  this,  as  in  all  other  develop- 
ment work,  the  most  serious  obstacle  comes  from  the  man  who 
will  not  see,  whether  it  be  from  a  lack  of  intelligence,  laziness  or 
inbred  opposition  to  all  forms  of  advancement. 


CHAPTER  XVII 
TOXIC    SMOKES 


ifi( 


le  introduction  of  diphenylchloroarsine  as  a  poison  gas 
really  introduced  the  question  of  toxic  smokes.  This  material,  as 
has  already  been  pointed  out,  is  a  solid,  melting  at  about  30°. 
In  order  to  secure  efficient  distribution,  the  material  was  mixed 
with  a  considerable  amount  of  high  explosive.  When  the  shell 
burst,  the  diphenylchloroarsine  was  finely  divided  or  atomized 
and  produced  a  cloud  of  toxic  particles.  Since  smoke  particles 
are  only  slightly  removed  by  the  ordinary  mask,  this  formed  a 
very  effective  means  of  chemical  warfare. 

An  analogous  result  was  obtained  by  the  use  of  poison  gases, 
such  as  chloropicrin,  in  a  smoke  cloud  produced  from  silicon  or 
stannic  chloride.  Here,  however,  the  toxic  material  was  a  real 
gas,  and  so  the  real  result  attained  consisted  in  forcing  the  men 
to  wear  their  masks  in  all  kinds  of  clouds.  The  true  toxic  smoke 
went  further  in  that  the  ordinary  mask  offered  little  protection 
and  thus  compelled  the  warring  nations  to  develop  a  special 
type  of  smoke  filter. 

These  smoke  clouds  consist  of  very  small  particles,  which  may 
be  considered  as  a  dispersed  phase,  distributed  in  the  air,  which 
we  may  call  the  dispersing  medium.  The  dispersed  phase  may 
be  produced  by  mechanical,  thermal,  or  chemical  methods. 

Mechanical  dispersion  consists  in  the  tearing  apart  of  the 
material  into  a  fine  state  of  subdivision.  It  may  be  called  a 
hammer  and  anvil  action.  The  more  powerful  the  mechanical 
force,  the  smaller  the  resulting  particles.  This  may  be  accom- 
plished by  the  use  of  a  high  explosive,  such  as  the  Germans  used 
in  the  case  of  diphenylchloroarsine. 

The  production  of  smoke  by  thermal  dispersion  depends 
essentially  upon,  the  fact  that  when  a  substance  of  sufficiently  low 
vapor  pressure  is  volatilized,  and  the  vapors  are  passed  into  the 

313 


314  CHEMICAL  WARFARE 

air,  they  re-condense  on  the  nuclei  of  the  air  to  form  a  smoke. 
Vaporization  from  an  open  container,  permitting  the  vapors  to 
pass  directly  to  the  air  without  being  quickly  carried  away  from 
the  surface  of  evaporation,  produces  smoke  having  larger  par- 
ticles, because  each  particle  formed  remains  for  an  appreciable 
period  of  time  in  contact  with  air  saturated  with  vapor,  and 
hence  grows  very  rapidly. 

The  easiest  way  to  produce  small  smoke  particles  is  to  mix 
the  toxic  material  directly  with  some  fuel  which  will  produce  a 
large  amount  of  heat  and  gas  upon  burning.  When  this  mixture 
is  enclosed  in  a  container  having  a  small  orifice,  upon  burning, 
the  toxic  vapor  and  gas  will  pass  through  this  orifice  at  high 
velocity;  it  has  been  demonstrated  by  Lord  Rayleigh  that  the 
size  of  the  particles  depends  upon  the  velocity  of  emission  of  the 
gas  from  a  given  orifice. 

The  product  of  chemical  combination  may  include  a  super- 
saturated vapor,  which  condenses  into  small  particles. 

Explosive  dispersion  is  really  a  combination  of  mecJianical 
dispersion  followed  by  thermal  dispersion. 

Penetration      n\ 

The  fundamental  idea  underlying  all  the  work  on  toxic 
smokes  is  to  obtain  a  smoke  that  has  marked  penetrating  power. 
Screening  power  is  not  important  here.  In  addition  to  penetra- 
tion, a  smoke  should  be  highly  toxic  and  have  a  slow  rate  of 
settling. 

Penetration  may  be  tested  by  the  use  of  a  standard  filter;  a 
suitable  filter  for  this  purpose  is  one  which  does  not  remove  the 
smoke  to  such  an  extent  that  measurement  of  its  concentration 
becomes  difficult,  and  one  which  does  not  become  clogged  quickly 
by  the  smoke.  A  filter  consisting  of  two  pads  of  felt,  placed  side 
by  side  and  arranged  so  that  the  smoke  first  comes  in  contact 
with  the  thinner  and  less  dense  pad  has  been  found  very  satis- 
factory. 

In  testing  penetration,  smoke  is  produced  by  dispersing  one 
gram  of  the  toxic  substance  in  a  sheet  iron  box  of  1000  liters 
capacity.  After  5  minutes  a  steady  concentration  is  usually 
attained  and  the  smoke  is  then  forced  through  a  Tyndall  meter. 


TOXIC  SMOKES 


315 


I 

H  (see  page  299)  after  dilution  with  air,  where  the  initial  con- 
centration is  determined.  It  then  passes  through  the  standard 
filter,  and  through  a  second  Tyndall  meter,  where  the  final  con- 
centration is  measured.  The  difference  of  the  two  readings  gives 
the  amount  of  smoke  retained  by  the  filter.  The  penetration  is 
ordinarily  represented  by  a  series  of  figures,  which  decrease 
from  a  maximum  value  at  the  beginning  of  the  test  to  a  minimum 
at  a  point  where  the  filter  permits  the  passage  of  so  little  smoke 


Fig.  100. — Penetration  Apparatus  Used  to  Test  Toxic  Smokes. 


that  it  cannot  be  measured.  This  decrease  is  due  to  decrease  in 
penetrating  power  and  concentration  of  the  smoke,  and  to  in- 
crease in  filtering  power  of  the  filter  as  a  result  of  plugging. 
Usually  five  degrees  of  penetration  are  recognized,  excellent, 
good,  fair,  poor  and  very  poor, 

A  portable  penetration  apparatus  is  shown  in  Fig.  100.  In 
using  the  apparatus,  the  smoke  producing  material  is  so  placed 
with  reference  to  the  apparatus  that  the  sample  is  taken  about 
20  feet  down  the  wind,  so  that  the  smoke  is  appreciably  diluted 
One  man  is  stationed  at  each  Tyndall  meter  and  takes  readings 


316  CHEMICAL  WARFARE 

as  fast  as  his  recorder  can  write  them,  so  that  the  smoke  density, 
before  and  after  the  filter,  can  be  followed  very  closely. 

Physiological  Action 

In  addition  to  a  high  penetrating  power  a  smoke  should  also 
possess  great  toxic,  irritant,  sternutatory,  or  lachrymatory 
power.  These  properties  are  tested  by  exposing  mice  to  the 
smoke  in  the  chamber.  They  are  placed  in  the  chamber  at  the 
beginning  of  the  run,  and  exposed  for  10  minutes  to  the  smoke 
from  1  gram  of  the  material.  While  these  tests  are  only  quali- 
tative in  character,  they  give  a  fairly  goocj  notion  of  the  relative 
value  of  different  materials. 

Quantitative  Relationships 

It  has  been  found  that,  if  the  optical  readings  from  the 
Tyndall  meter  are  plotted  as  ordinates  against  the  time  t  (the 
time  elapsed  after  detonation)  as  abcissas,  and  that  portion  of 
the  curve  between  t=0  and  ^=30  considered,  the  curve  generally 
descends  sharply  at  first,  from  a  high  point  representing  the 
density  immediately  after  the  production  of  the  smoke,  to  a 
point  in  the  neighborhood  of  t=8,  where  it  flattens  out  and 
descends  much  more  slowly  with  a  slope  that  changes  little.  The 
area  under  the  significant  portion  of  the  curve,  that  is,  the  area 
circumscribed  by  the  curve  from  the  point  t^o  to  (q,  the  vertical 
axis  from  this  point  to  the  origin,  the  horizontal  axis  from  the 
origin  to  ^30  and  the  line  perpendicular  to  this  axis,  cutting  the 
curve  at  t^Q,  is  a  rough  measure  of  the  relative  values  of  different 
smokes.  This  area  is  calculated  as  the  sum  of  two  rectangles, 
from  to  to  #8  and  from  fg  to  ^30- 

Some  results  are  as  follows : 

Area  30 

Phenyl  dichloroarsine 181 

Triphenyldichloroarsine 178 

;    Diphenylcyanoarsine 1 37 

Diphenylchloroarsine 101 

Cyanogen  bromide 94 

Methyl  dichloroarsine 70 

Phenylimidophosgene 69 

Mustard  gas 38 


TOXIC  SMOKES 


317 


The  curves  in  Fig.  101  show  the  way  in  which  the  readings 
fall  off  with  time.  Each  substance  of  course  has  its  characteristic 
curves. 


18.0 

17.4 

16.8 

/ 

16.2 

16.6 

15.0 

1 

14.4 

1 

13.8 

\ 

13.2 

\ 

12.6 

\ 

12.0 

\ 

01.4 

►^10.8 
|l0.2 
M   0.6 

\                                      Phenyl-di-chlor-Arsine  Detonations 

\                                     Curve  No. 1-2  gm.  Phenyl-di-chlor-arsine 

\                                    Curve  No. 2-5  gm.    Phenyl-di-chlor-arsine 

A        \                                   Curve  No. 3-1  gm.   Phenyl  diofclor-arsine 

^        \                                 Curve  No. 4-0. 5gm. Phenyl-di-chlor-arsine 

ft        \                              Curve  No  5-3  gm.    Phenyl-di-chlor.arsinc 

E    8.4 
|,.8 
=    7-2 
"   6.6 

l\\ 

^o.6  Detonators 

6.0 

-    \            \      \ 

5.4 

-  V    \   \^ 

4.8 

\\           \\             N. 

4.2 

\/\\\.         \^ 

3.6 

^v>^>^ 

X 

. 

•  3.0 

\s^^  x:^ 

^ 

^\^ 

2.4 

^\^^ 

^^^"^^^ZT""^^-^ 

1.8 
1.2 
.6 

^^""^-^5      *                3 

Fig.  101.- 


2    4   6  81012141G182022242G2S30;J23-43C3S4042444C4850o254565860 
Time-lliiiutea 

-Typical  Curves  Showing  the  Decrease  in  Concentration 
Cloud  with  Time. 


of  Smoke 


^ 


Toxic  Materials 


The  selection  of  materials  for  the  production  of  toxic  smokes 
can  only  be  carried  out  experimentally.  A  number  of  very  toxic 
substances  have  been  shown  to  be  valueless  as  toxic  smokes 
because  of  low  penetration,  decomposition  during  the  process  of 
smoke  production,  or  for  other  reasons. 


318  CHEMICAL  WARFARE 

Arsenic  compounds  produce  smokes  distinctly  better  than  the 
average.  Inorganic  compounds  which  have  high  melting  and 
boiling  points  are  very  poor  smoke  producers.  The  only  excep- 
tion to  this  is  magnesium  arsenide,  which  may  suffer  decom- 
position. Compounds  like  mercuric  chloride  and  arsenic  tri- 
bromide,  which  boil  or  sublime  at  comparatively  low  tempera- 
tures, produce  good  smokes.  Most  materials  which  boil  below 
130°  C.  produce  no  smoke  as  they  evaporate  on  dispersion.  It  is 
difficult  to  set  any  upper  limit  for  the  boiling  point  beyond  which 
materials  do  not  produce  good  smokes,  but  in  all  probability 
500°  C.  is  not  far  from  the  maximum.  Liquids  and  solids  are, 
on  the  whole,  almost  equally  good  as  smoke  producers.  The 
physical  condition  of  the  material  has  no  great  effect  upon  the 
amount  of  smoke  which  it  will  produce.  This  seems  to  depend 
only  upon  the  physical  and  chemical  properties  of  the  material. 

Toxic  Smoke  Apparatus 

It  has  been  mentioned  above  that  the  Germans  used  a  shell, 
containing  solid  diphenylchloroarsine  and  a  high  explosive.  A 
10.5  cm.  shell  (Blue  Cross)  was  about  two-thirds  filled  with  cast 
trinitrotoluene  and  contained  a  glass  bottle  with  300-400  grams 
of  toxic  material.  Diphenylchloroarsine  was  also  used  in  shell,  in 
solution,  a  mixture  of  phosgene  and  diphosgene  (superpalite) 
being  the  ordinary  solvent  (Green  Cross).  Mixtures  of  di- 
phenylchloroarsine and  phenyldichloroarsine  were  also  used. 

In  the  case  of  high  explosive  shell,  the  use  of  a  separate  con- 
tainer appears  to  be  desirable,  because  a  mixture  with  the  ex- 
plosive seriously  decreases  its  sensitiveness  and  even  its  destruc- 
tive power.  There  is  also  a  question  as  to  the  stability  of  such  a 
mixture.  However,  75  mm.  shell  containing  30  per  cent  di- 
phenylchloroarsine mixed  with  T.  N.  T.  gave  good  clouds  of  toxic 
smoke. 

Toxic  Smoke  Candle  -^ 

Two  toxic  smoke  candles  were  developed  by  the  Chemical 
Warfare  Service,  known  as  the  B-M  Toxic  Smoke  Candle,  per- 
fected by  the  Pyrotechnic  Section  of  the  Research  Division, 
and  the  Dispersoid  Smoke  Candle,  developed  by  the  Dispersoid 
Section. 


TOXIC  SMOKES 


319 


The  B-M  Toxic  Smoke  Candle  consists  of  a  bottle-shaped 
sheet-steel  toxic  container  set  into  a  can,  containing  smoke 
mixture.  The  heat  from  the  burning  mixture  causes  the  dis- 
tillation of  the  toxic  material.  The  toxic  vapor  is  discharged 
through  a  nipple,  screwed  into  the  neck  of  the  container  and 
extending  over  the  top  of  the  smoke  can.  Steel  wool  is  used 
in  the  toxic  container  to  reduce  the  violent  boiling  and  spat- 
tering of  the  material.    A  small  amount  of  steel  wool,  held  in 


Fig.  102— Toxic  Smoke  Cloud  from  500  D.  M.  Candles. 

The  candles  were  placed  in  5  parallel  rows  which  were  2  yards  apart,  each  row  contain- 
,  ing  100  candles  on  a  100  yard  front.     The  total  time  of  active  smoke  emission  was 

23  minutes. 


place  by  a  wire  screen,  is  also  used  in  the  nipple  for  the  same 
purpose.  The  toxic  container  is  sealed  by  a  fusible  metal  plug, 
melting  at  90°  C,  cast  into  a  retainer  at  the  base  of  the  nipple. 
The  fusible  plug  melts  upon  the  first  application  of  heat  and 
allows  free  passage  of  the  vapor  into  the  smoke  cloud.  The 
ignition  of  the  apparatus  is  effected  by  means  of  a  simple  match 
head  and  an  accompanying  scratcher. 

The  first  evolution  of  smoke  occurs  about  10  seconds  after 
tlie  first  appearance  of  flame.  About  one  minute  after  ignition 
the  toxic  material  will  begin  to  distill  into  the  smoke  cloud 


320  CHEMICAL  WARFARE 

and  this  will  continue  for  about  four  minutes.     The  burning 
of  the  candle  should  be  complete  in  about  six  minutes. 

The  Dispersoid  Toxic  Smoke  Candle  differs  from  the  B-M 
candle  in  that  the  toxic  container  is  not  used.  A  mixture  of 
smokeless  powder  and  the  toxic  material  (diphenylchloroarsine 
or  D.  M.,  an  arsenical  obtained  from  arsenic  trichloride  and 
diphenylamine)  is  filled  directly  into  the  container,  a  cylindrical 
can  3.5  inches  in  diameter  and  9  inches  high  made  from  27  gauge 
sheet  metal,  and  packed  under  a  total  pressure  of  2,500  pounds. 
The  top  of  the  candle  is  a  metal  cover,  containing  the  match  head 
scratcher,  which  is  separated  from  the  match  head  by  a  Manila 


\ 


Dispersoid  Candle  British  Candle 

Fig.  103.— Comparison  of  Dispersoid  and  British  D.  M.  Candles. 

paper  disc.  These  are  the  same  as  those  used  in  the  B-M 
candle.  The  candle  has  a  total  weight  of  about  4.25  pounds, 
of  which  3.6  pounds  are  the  smoke  mixture,  containing  about 
1.3  pounds  of  toxic  material. 

In  operating  the  candles,  the  cover  is  removed  and  the 
match  head  ignited  by  friction  with  the  scratcher.  The  match 
head  burns  through  the  cardboard  and  ignites  the  powder.  The 
heat  and  gas  produced  by  the  combustion  of  the  powder  vapor- 
izes the  particles  of  the  toxic  material  and  carries  the  vapors 
out  through  the  orifices  at  a  high  velocity  whereupon  they 
recondense  to  form  a  smoke.  The  rapid  emission  of  the  vapors 
through  the  orifice  prevents  any  possibility  of  their  ignition. 

The  time  before  good  emission  of  smoke  takes  place  after 


TOXIC  SMOKES  321 

the  ignition  of  the  match  tip  of  a  candle  is  30  seconds.  The 
average  time  of  vigorous  smoke  emission  is  from  four  to  five 
minutes.  The  result  of  a  field  test  with  the  dispersoid  candle 
is  shown  in  Fig.  102.  A  comparison  of  a  British  and  a  Disper- 
soid candle  is  shown  in  Fig.  103.  It  should  be  stated  that  this 
may  not  have  been  a  fair  test  as  only  one  British  candle  was 
available  for  the  comparative  test. 


CHAPTER   XVIII 
SMOKE   FILTERS 

The  first  types  of  the  Standard  Box  Eespirator  contained 
cotton  pads,  which  sufficed  to  remove  the  ordinary  smoke  of 
the  battlefield  and  even  that  from  the  earlier  toxic  materials. 
Improved  methods  of  producing  toxic  smokes,  by  means  of 
which  smaller  particles  were  obtained,  led,  early  in  1918,  to 
the  recognition  of  the  need  of  improved  protection  against 
these  smokes.  The  first  attempts  to  meet  this  need  consisted 
in  improving  the  filtering  qualities  of  these  pads.  It  was  soon 
found,  however,  that  to  make  better  filter  pads  would  greatly 
increase  the  total  resistance  of  the  canister.  This  was  highly 
undesirable,  since  the  resistance  of  the  ordinary  canister  was 
already  so  high  as  to  be  very  uncomfortable.  To  overcome 
this  objection,  some  of  the  early  designs  of  filter  canisters 
were  provided  with  a  mechanical  valve,  which  could  be  operated 
by  hand,  to  by-pass  the  air  around  the  filter  when  the  canister 
was  used  against  gas  alone,  or  so  set  as  to  make  the  air  pass 
through  the  filter  when  smoke  was  feared.  This  introduced 
a  factor  of  uncertainty  among  the  men  during  a  gas  attack, 
since  each  man  must  decide  for  himself  whether  smoke  was 
present.  This  reason  alone  was  sufficient  for  discarding  this 
design. 

A  preliminary  study  of  the  situation  indicated  that  any 
filter  for  fine  smoke  particles  must  have  a  high  resistance  per 
unit  of  area,  but  that  the  total  resistance  must  be  compara- 
tively low.  In  order  to  secure  the  large  area  necessary  to 
bring  the  total  resistance  within  reason,  the  experimental  work 
was  developed  along  three  lines :  The  formation  of  a  filter  into 
a  bag,  cup,  or  jacket  to  surround  the  outside  of  the  canister; 
the  use  of  an  arrangement  sufficiently  compact  to  go  inside 

322 


SMOKE  FILTERS 


323 


the  canister;  and  the  use  of  a  filter  as  a  separate  unit,  to  be 
attached  to  the  canister  by  an  air  connection. 

A  survey  of  the  possible  filtering  materials  indicated  that 
only  two  offered  promise,  namely,  paper  and  felt. 

Paper  Filters 

Reports  that  the  British  had  developed  thin,  creped,  sulfite- 
cellulose  wood  pulp  paper  for  filters  led  to  an  intensive  study 
of  this  material  by  the  Chemical  Warfare  Service. 


'Fig.  104, — Crepe  Paper  Doughnut  Filter  Canister. 

In  general  we  may  say  that  the  development  of  paper  filters 
(in  sheet  form)  met  with  little  success.  Papers  affording  the 
required  protection  did  not  live  up  to  the  resistance  specifica- 
tions. The  reason  for  this  probably  is  in  the  method  of  making 
paper.  The  pulp  is  fed  onto  the  screen  of  a  Fourdrinier 
machine  under  conditions  that  do  not  permit  of  uniformity 
in  the  distribution  of  the  fibers  and  consequently  there  is  no 
uniformity  in  the  size  of  pores.  In  order  to  eliminate  the 
large  holes,  which  allow  the  smoke  to  pass  readily,  the  paper 


324  CHEMICAL  WARFARE 

must  be  pressed  to  reduce  these  pores  to  the  proper  magnitude. 
This  naturally  results  in  an  approximately  equal  decrease  in 
the  size  of  the  small  pores,  with  a  consequent  increase  in  the 
final  resistance  out  of  all  proportion  to  the  protection  gained. 
A  very  satisfactory  paper  was  finally  produced,  but  the  resist- 
ance was  too  high  and  it  was  necessary  to  increase  the  total 
available  filtering  area,  which  resulted  in  the  accordion  type 
of  filter.  This  filter  was  incapable  of  development  on  a  large 
scale  because  of  the  large  amount  of  hand  work  required  in 
assembling.  The  lack  of  uniformity  in  a  single  sheet  has  been 
overcome  with  some  success  by  making  up  a  filter  from  40  to 
80  layers  of  tissue  or  crepe  paper,  trusting  that  the  law  of 
chance  would  bring  the  large  pores  in  some  successive  layer. 
Such  a  filter  was  adopted  by  the  British,  but  since  it  did  not 
give  protection  comparable  with  that  aij^orded  by  felt  filters, 
it  was  rejected  in  the  United  States. 

In  the  so-called  '* doughnut"  filter  use  was  made  of  tissue 
paper.  Instead  of  seeking  for  uniformity  in  a  vertical  direc- 
tion through  a  block  of  tissues,  it  was  sought  along  the  axis 
horizontal  with  the  sheet.  The  effectiveness  of  such  a  filter 
was  less  than  that  of  felt.  In  addition,  serious  difficulty  was 
met  in  cutting  the  pile  of  tissue  paper  into  the  proper  shape 
so  that  eventually  it  was  abandoned  as  a  production  possibility. 

Felt  Filters 

Work  on  the  felt  filters  started  about  June,  1918.  Great 
difficulties  were  met  in  the  beginning,  as  a  felt  satisfactory 
for  this  purpose  must  be  made  under  carefully  controlled 
conditions  and  production  conditions  during  the  war  did  not 
readily  lend  themselves  to  such  control.  However,  the  oppor- 
tunities afforded  in  felt  making  for  uniform  packing  and 
arranging  of  the  fibers  (the  whole  process  of  making  a  felt 
is  one  of  gradual  packing  of  fibers  into  a  relatively  small 
volume)  are  such  as  to  assure  a  greater  degree  of  success 
than  is  the  case  in  paper  making. 

Very  successful  filters  have  been  obtained  with  the  use 
of  felt.  There  are  two  serious  objections  to  its  use,  however. 
The  first  is  the  great  cost  of  the  filter   (this  was  above  one 


SMOKE  FILTERS 


325 


dollar  per  filter  at  the  close  of  the  War)  ;  the  second  is  that 
felt  is  a  valuable  industrial  commodity.  It  is  thus  very  desir- 
able that  a  cheaper  and  a  less  important  industrial  material  be 
found. 

The  1919  Canister 

Just  before  the  Armistice,  the  Gas  Defense  Long  Island 
Laboratory  brought  out  the  so-called  ''1919  Canister,"  which 
consisted  of  an  oval  section,  perforated  metal,  war  gas  material 


Fig.  105.— 1919  Felt  Filter  Canister. 


container  with  a  central,  flat,  perforated  breathing  tube  con- 
nected to  a  nozzle  at  one  end.  (See  also  page  228.)  After  this 
inner  container  is  packed  with  the  war  gas  chemicals,  a  filter 
jacket  is  slipped  over  it  and  the  top  edge  sealed  to  the  inner 
container. 

Attempts  were  made  to  put  paper  filters  on  this  canister 


326  CHEMICAL  WARFARE 

by  wrapping  it  with  layers  of  paper.  In  some  cases,  layers 
of  coarse  burlap  or  mosquito  netting  were  applied  between 
the  layers  of  paper  to  give  mechanical  strength  and  air  space. 
The  fact  that  many  filters  gave  good  protection  showed  that 
a  filter  of  this  type  and  material  is  possible,  but  the  operations 
of  wrapping  and  sealing  require  careful  work  in  production 
and  inspection  and  even  with  the  greatest  skill  and  care, 
imperfections  are  almost  impossible  to  avoid.  This  chance  of 
defects,  together  with  the  labor  involved,  makes  the  process 
undesirable. 

A  Theory  op  Smoke  Filters 

Tolman,  "Wells  and  Gerke,  during  the  course  of  their  work 
on  toxic  smokes,  developed  the  following  theory  of  smoke 
filters. 

The  phenomena  occurring  in  the  filtration  of  smoke  are 
exceedingly  complicated,  but  the  general  nature  of  the  process 
may  be  simply  described  in  terms  of  the  kinetic  properties  of 
the  small  particles  comprising  the  smoke. 

A  filter  may  be  regarded  as  a  series  of  minute  capillaries 
through  which  the  smoke  slowly  flows.  In  order  that  filtration 
may  take  place,  it  is  not  necessary  to  assume  that  the  capil- 
laries of  the  filter  are  smaller  than  the  particle,  for  the  particles 
may  diffuse  to  the  walls  of  the  capillaries  and  it  is  believed 
that  with  typical  filters  this  is  the  actual  method  of  smoke 
removal  for  particles  less  than  10-*  cm.  in  diameter. 

In  accordance  with  this  view  as  to  the  nature  of  smoke 
filtration,  the  important  factors  involved  are  (1)  the  Brownian 
motion  of  the  smoke  particles,  (2)  the  area  and  arrangement 
of  the  internal  surface  presented  by  the  filter,  (3)  the  flow 
of  the  smoke  as  a  whole,  and  (4)  the  attractive  forces  between 
the  filter  surfaces  and  the  smoke  particles.  The  first  three 
of  these  factors  determine  how  many  particles  come  within 
the  range  of  the  mutual  forces  of  the  particle  and  filter  surface, 
and  the  fourth  factor  determines  the  chance  or  expectation 
that  the  particle  will  permanently  adhere  to  the  surface  of 
the  filter. 


I 


tiMOKE  FILTERS  327 

Testing  Smoke  Filters 

All  the  early  tests  made  on  smoke  filters  used  diphenyl- 
chloroarsine,  because  it  was  felt  that  the  filter  must  be  tested 
against  a  toxic  smoke.  A  man  test  was  developed  as  repre- 
sentative as  possible  of  actual  conditions  in  the  field,  and  the 
time  necessary  for  a  man  to  detect  diphenylchloroarsine  smoke 
in  the  effluent  stream  when  breathing  at  a  normal  rate,  using 
a  carefully  controlled  concentration  of  smoke  produced  by 
detonation,  was  used  as  the  criterion  of  the  protection  offered 
by  the  canister.  This  test  was  subject  to  extensive  individual 
variations,  due  to  the  varying  physiological  resistances  of 
different  men  to  diphenylchloroarsine  smoke.  Further,  it  was 
quite  inadequate  for  rapid  testing  on  a  large  scale.  A  testing 
machine  was  then  developed,  which  gave  results  comparable 
with  those  obtained  in  the  man  test.  The  method  used  in 
detecting  the  gas  was  physiological,  that  is,  by  smell  or  by 
its  irritating  action  towards  the  membranes  of  the  eye.  While 
these  are  purely  qualitative  tests,  they  are  much  more  sensi- 
tive than  any  possible  chemical  tests. 

Because  of  the  desirability  of  having  a  method  which  could 
be  controlled  chemically,  other  methods  were  developed. 

Ammonium  chloride  is  a  solid  smoke,  consisting  of  particles 
of  quite  variable  sizes.  It  is  sensitive  to  dilution  and  clogs 
the  pores  of  the  filtering  medium  quite  rapidly.  For  this 
reason  it  was  used  in  the  study  of  the  rate  of  plugging  or 
clogging  of  the  filter  (the  closing  of  the  pores  of  the  fabric 
or  other  material  to  the  passage  of  air). 

The  smoke  is  produced  by  the  reaction  of  ammonia  and 
hydrogen  chloride-air  streams.  The  smoke  thus  generated 
is  passed  from  the  mixing  chamber  to  a  larger  distribution 
box  and  from  there  through  the  filter,  at  a  standard  rate. 
The  concentration  of  the  smoke  may  be  accurately  determined 
by  chemical  means  or  photometrically,  using  a  Hess-Ives  Tint 
Photometer,  the  Marten  Photometer,  or  a  special  photometer 
developed  by  the  Chemical  Warfare  Service. 

A  comparison  of  a  large  number  of  tests  with  those  of 
other  smokes  would  indicate  that  ammonium  chloride  smoke 


328 


CHEMICAL  WARFARE 


offers  accurate  information   as   to   protection  sought,   but  is 
hardly  a  desirable  smoke  for  testing  on  a  large  scale. 

The  third  method  developed  was  the  sulfuric  acid  smoke. 
This  smoke  was  produced  by  passing  dry  air  through  a  tower 
of  solid  pieces  of  sulfur  trioxide  and  then  mixing  the  vapor 
with  a  large  volume  of  air  at  50  per  cent  relative  humidity. 
It  is  not  a  clogging  smoke  and  the  filtering  efficiency  does 


Fig.    106. — Tobacco  Smoke  Apparatus  for  Testing  Canisters. 


not  change  materially  in  the  time  of  exposure  required  for  a 
test.  The  smoke  lends  itself  easily  to  chemioal  analysis  and 
offers  data  as  to  exact  particulate  cloud  concentrations  which 
will  penetrate  canisters;  photometric  measurements  are  also 
applicable. 

The  fourth  method  consists  in  the  use  of  tobacco  smoke. 
This  is  generated  by  passing  air  over  ignited  sticks  of  a 
mixture  of  tobacco    (63  per  cent),  rosin   (30  per  cent)    and 


I 


SMOKE  FILTERS  329 


potassium  nitrate  (7  per  cent).  This  smoke  is  composed  of 
particles  of  extreme  uniformity  in  size;  chemically  it  is  rela- 
itvely  inert.  It  is  not  a  clogging  smoke  and  is  not  sensitive 
to  moisture  and  dilution.  The  density  of  the  effluent  smoke 
is  compared  with  that  of  the  entering  smoke  in  a  Tyndall 
beam,  and  the  filtering  capacity  of  the  material  determined 
in  terms  of  the  amount  of  air  necessary  to  dilute  the  entering 
air  to  the  same  concentration  of  the  effluent  air.  The  method 
is  simple  in  manipulation  and  the  test  is  a  rapid  one  (50 
canisters  per  day).  Because  of  the  apparent  superiority  of 
tobacco  smoke  as  a  testing  smoke,  the  accompanying  disad- 
vantages are  possibly  outweighed. 

From  the  standpoint  of  inherent  chemical  properties,  the 
general  desirability  of  a  suitable  testing  smoke  would  decrease 
in  the  following  order:  tobacco,  sulfuric  acid,  ammonium 
chloride. 


CHAPTER   XIX 

SIGNAL   SMOKES 

/  The  success  of  pyrotechnics  in  night  signalling  led,  during 
'the  World  War,  to  considerable  attention  being  paid  to  the 
development  of  pyrotechnic  signals  for  day  use.  This  was 
mainly  directed  to  the  production  of  distinctive  smokes,  which 
should  have  the  same  long  range  visibility  under  varying  light 
conditioils.  Since  a  gray  or  white  smoke  might  be  confused 
with  the  smoke  produced  accidentally  by  the  explosion  of 
shell,  it  was  necessary  to  use  smoke  of  definite  and  unmistak- 
able colors,  and  red,  blue,  yellow,  green  and  purple  smokes 
were  developed.  During  the  early  part  of  the  war,  only  a 
yellow  smoke  was  in  use,  though  others  were  added  later. 

Production  of  Colored  Smokes 

There  are  three  possible  ways  of  obtaining  signal  smokes. 
I.  Mechanically  dispersing  solids. 
II.  Chemical  Reaction. 

III.  Volatilization  of  colored  materials. 

I^  The  first  method,  while  possible,  can  never  be  an  efficient 
method  of  producing  signals.  Some  success  was  met  with  in 
dispersing  certain  inorganic  materials,  as  rouge,  and  ultrama- 
rine, in  projectiles  fired  from  a  3-inch  mortar  and  exploded  by 
a  time  fuse  arrangement  at  the  height  of  their  flight.  Various 
mixtures  were  also  tried,  such  as  antimony  oxysulfide  and 
aluminum  powder  (red),  arsenic  and  antimony  trichlorides 
with  sodium  thiosulfate  (yellow),  etc.,  but  these  compositions 
have  the  disadvantages  of  being  liable  to  catch  fire  if  dispersed 
by  a  black  powder  explosion. 

II.  While  colored  smokes  may  be  produced  by  chemical  re- 
action, such  as  the  combination  of  hydrogen  iodide  (HI),  chlor- 

330 


I 


SIGNAL  SMOKES  331 


ine  and  ammonia,  the  clouds  are  not  satisfactory  as  signals.  In 
this  particular  case,  the  purple  cloud  (to  the  operator  in  the 
aeroplane)  appeared  white  to  the  observers  on  the  ground. 

High  temperature  combustion  smokes  have  also  been  studied. 
These  are  used  in  the  so-called  smoke  torches.  The  yellow  arsenic 
sulfide  smoke  is  the  most  widely  used.  Most  formulas  call  for 
some  sulfide  of  arsenic  (usually  the  native  realgar,  known  com- 
mercially as  '*Eed  Saxony  Arsenic"),  sulfur,  potassium  nitrate, 
and  in  some  cases,  a  diluent  like  ground  glass  or  sand.  A  typical 
mixture  consists  of: 

Red  arsenic  sulfide 55% 

Sulfu^ 15% 

Potassium  nitrate 30% 

A  very  similar  smoke  may  be  obtained  from  the  following 
mixture : 

Sulfur 28.6% 

White  arsenic 32.0% 

Potassium  nitrate 33 .8% 

Powdered  glass 6.6% 

These  smokes  are  not  as  satisfactory  in  color  as  the  smoke 
produced  by  a  dye  smoke  mixture,  especially  when  viewed  from 
a  distance,  with  the  sky  as  a  background.  They  fade  out  rather 
quickly  to  a  very  nearly  white  smoke. 

A  black  smoke  upon  first  thought  might  seem  to  be  the 
easiest  of  all  smokes  to  produce,  but  actually  the  production  of  a 
black  smoke  that  would  be  satisfactory  for  signalling  purposes 
was  rather  a  difficult  matter. 

Starting  with  the  standard  smoke  mixture,  which  gives  a 
white  or  gray  smoke,  hexachloroethane,  which  is  solid,  was  sub- 
stituted for  the  carbon  tetrachloride,  in  order  to  avoid  a  liquid 
constituent.  Naphthalene  was  first  used,  until  it  was  found  that 
the  mixture  of  naphtalene  and  hexachloroethane  melted  at  tem- 
peratures below  that  of  either  of  the  constituents.  Anthracene 
was  then  substituted.  The  principal  reaction  is  between  the 
magnesium  and  the  chlorine-containing  compound,  whereby 
magnesium  chloride  and  carbon  are  formed.  The  reaction  is 
very  violent,  and  a  white  smoke  is  produced.  The  anthracene 
slows  down  the  reaction  and  at  the  same  time  colors  the  smoke 


332  CHEMICAL   WARFARE 

black.  The  speed  of  the  reaction  may  be  controlled  by  varying 
the  anthracene  content. 

In  burning  this  type  of  smoke  mixture  in  a  cylinder,  it  is 
essential  that  free  burning  be  allowed.  It  has  been  found  that  if 
combustion  is  at  all  smothered,  and  the  smoke  forced  to  escape 
through  a  comparatively  small  opening,  it  will  be  gray  instead 
of  dense  black. 

III.  Various  attempts  have  been  made  to  utilize  the  heat 
evolved  when  the  Berger  type  smoke  mixture  reacts  to  volatilize 
or  mechanically  disperse  various  colored  inorganic  substances, 
and  especially  iodine.  These  were  unsuccessful.  Modifications, 
such  as 

Strontium  nitrate 1  part 

Powdered  ircn 2  parts 

Iodine 3  parts 

were  also  tried,  but  while  such  mixtures  ignited  easily,  burned 
freely  and  evenly,  and  gave  a  continuous  heavy  purple  cloud, 
they  were  very  sensitive  to  moisture  and  capable  of  spontaneous 
ignition. 

The  most  satisfactory  and  successful  colored  smokes  arc 
those  produced  by  the  volatilization  of  organic  dye  materials. 
This  practice  seems  to  have  originated  with  the  British,  who 
produced  such  smokes  by  volatilizing  cr  vaporizing  special  dyes 
by  igniting  mixtures  of  the  dye,  lactose  and  potassium  chlorate 
and  smothering  the  combustion. 

In  selecting  dyestufPs  for  this  purpose  it  was  at  once  recog- 
nized that  only  those  compounds  can  be  used  which  are 
volatilized  or  vaporized  without  decomposition  by  the  heat 
generated  when  the  mixture  is  ignited  and  the  combustion 
smothered.  It  was  also  found  that  the  boiling  point  and  melting  or 
volatilization  point  of  the  colored  compound  must  be  close  enough 
together  so  that  there  is  never  much  liquid  dye  present.  Since 
all  colored  organic  compounds  are  destroyed  if  subjected  to 
sufficient  heat,  the  mixture  must  be  so  prepared  and  the  ignition 
so  arranged  that  the  heat  generated  is  not  sufficient  to  cause  this 
destruction. 

The  oxidizing  agents  used  in  the  combustion  mixture  may  be 
either  potassium  or  sodium  chlorate.    The  nitrate  is  not  satisfac- 


SIGNAL  SMOKES  333 

toiy.  Lactose  has  proven  the  best  combustible.  Powdered 
orange  shellac  is  fairly  satisfactory  but  offers  no  advantage  over 
lactose. 

The  following  dyes  have  been  found  to  give  the  best  smokes : 

Red "Paratoner" 

Yellow Chrysoidine+Auramine 

Blue Indigo 

Purple Indulin  (?) 

Green Auramine  Yellow  +Indigo 

At  the  beginning  of  the  war,  the  only  colored  smoke  used  by 
the  United  States  Army  was  a  yellow  smoke.  The  smoke  mixture 
used  in  all  signals,  excepting  the  smoke  torch,  was  the  old  arsenic 
sulfide  mixture.  The  following  smoke  signals  were  adopted  dur- 
ing the  World  War : 

Signal  Parachute  Rocket Yellow  and  Red 

V.  B.  Parachute  Cartridge Yellow 

25  mm.  Very  Parachute  Cartridge Yellow 

35  mm.  Signal  Cartridge Yellow 

35  mm.  Signal  Cartridge Red 

35  mm.  Signal  Pistol 

25  mm.  Very  Signal  Pistol 

V.  B.  Rifle  Discharger  Cut 

The  Tactical  Use  of  Signal  Smokes 

From  the  days  when  Horatius  kept  the  bridge,  down  through 
the  centuries  to  the  World  War,  all  leaders  in  battle  were 
pictured  at  the  front  and  with  flaming  sword,  mounted  on 
magnificent  chargers,  or  otherwise  so  prominently  dressed  that 
all  the  world  knew  they  were  the  leaders.  During  all  these* 
hundreds  of  years  commands  on  the  field  of  battle  were  by  the 
voice,  by  the  bugle,  or  by  short  mnge  signals  with  arms,  flags, 
and  swords.  Even  where  quite  large  forces  were  involved  they 
were  massed  close  enough  ordinarily  so  that  signalling  by  such 
means  sufficed  to  cover  the  front  of  battle.  In  those  cases  where 
they  did  not,  reliance  was  put  upon  swift  couriers  on  horseback 
or  on  foot. 

With  the  invention  of  smokeless  powder  and  the  rifled  gun 
battles  were  begun  and  carried  on  at  greater  and  greater  ranges. 
Artillery  fired  not  only  2,000  to  3,000  yards  but  up  to  5,000  and 


334  CHEMICAL  WARFARE 

10,000  yards,  or  even,  as  in  the  World  War,  at  20,000  yards  and 
more.  It  was  then  that  other  means  of  signalling  became  essen- 
tial. Distant  signalling  with  flags  is  known  to  have  been  prac- 
ticed to  a  certain  extent  on  land  for  a  long  time.  The  extension 
of  the  telegraph  and  telephone  through  insulated  wires  laid  by 
the  Signal  Service  was  the  next  great  step  in  advance,  and  in 
the  World  War  there  came  in  addition  the  wireless  telephone 
both  on  land  and  in  aeroplanes  and  balloons. 

Along  with  this  development,  as  mentioned  under  Screening 
Smokes,  came  the  development  of  the  use  of  smoke  for  protection 
and  for  cutting  off  the  view  of  observers,  thus  making  obser- 
vation more  and  more  difficult.  This  use  of  smoke,  coupled  with. 
the  deadly  fire  of  machine  guns  and  high  explosives,  forced  men 
to  take  shelter  in  deep  shell  holes,  in  deep  trenches  and  other 
places  that  were  safe,  but  which  made  it  nearly  impossible  to 
see  signals  along  the  front  of  battle. 

Every  man  can  readily  be  taught  to  read  a  few  signals  when 
clearly  indicated  by  definite,  sharply  defined  colored  smokes. 
At  first  these  were  designed  for  use  on  the  ground  and  will  be 
used  to  a  certain  extent  in  the  future  for  that  purpose,  par- 
ticularly when  it  is  desired  to  attract  the  attention  of  observers 
in  aeroplanes  or  balloons.  In  such  cases  a  considerable  volume  of 
smoke  is  desired.  For  the  man  in  the  trench  or  shell  hole  some 
means  of  getting  the  signal  above  the  dust  and  smoke  of  the 
battlefield  is  needed.  It  is  there  that  signal  smokes  carried  by 
small  parachutes,  contained  in  rockets  or  bombs,  have  proven 
their  worth.  These  signals  floating  high  above  the  battlefield 
for  a  minute  or  more,  giving  off  brilliantly  colored  smokes, 
afford  a  means  of  sending  signals  to  soldiers  in  the  dust  and 
smoke  of  battle  not  afforded  by  any  other  method  so  far  invented. 
As  before  stated,  every  man  can  be  taught  these  simple  signals, 
where  but  very  few  men  can  be  taught  to  handle  even  the 
simplest  of  wireless  telephones. 

Thus,  smoke  has  already  begun  to  complicate,  and  in  the 
future  will  complicate  still  more,  every  phase  of  fighting.  It 
will  be  used  for  deception,  for  concealment,  for  obscuring  vision, 
for  signalling  and  to  hide  deadly  gases.  The  signal  rocket  will 
be  used  to  start  battles,  change  fronts,  order  up  reserves,  and 
finally  to  stop  fighting. 


SIGNAL  SMOKES  335 

The  signal  smokes  by  day  will  be  displaced  at  night  by 
brilliantly  colored  lights  which  will  have  the  same  meaning  as 
similarly  colored  smokes  during  the  day.  Thus,  literally,  smoke  in 
the  future  will  be  the  cloud  by  day  and  the  pillar  of  fire  by  night 
to  guide  the  bewildered  soldier  on  the  field  of  battle  with  all  its 
terrors  and  amidst  the  confusion,  gas,  smoke  and  dust  that  will 
never  be  absent  while  battles  last. 


CHAPTER  XX 
INCENDIARY   MATERIALS 

Since  it  is  generally  known  that  white  phosphorus,  when 
exposed  to  the  air,  takes  fire  spontaneously,  it  logically  follows 
that  numerous  suggestions  should  have  been  made  for  using  this 
material  in  incendiary  devices.  Practice,  however,  has  shown 
that,  while  phosphorus  is  undoubtedly  of  value  against  very 
easily  ignitable  materials,  such  as  hydrogen  in  Zeppelins,  or  the 
gasoline  tanks  of  aeroplanes  and  dry  brush  or  grass,  it  is  of 
much  less  value  when  wood  and  other  materials  are  considered. 
This  is  partly  because  of  the  low  temperature  of  burning,  and 
partly  because  the  product  of  combustion  (phosphoric  anhy- 
dride) is  really  an  excellent  fireproofing  substance.  In  view  of 
this,  phosphorus  was  used  primarily  for  smoke  production. 

A  superior  incendiary  material  is  found  in  thermit,  a  mixture 
of  aluminum  and  iron  oxide.  When  ignited,  it  produces  an 
enormous  amount  of  heat  very  quickly,  and  the  molten  slag  that 
results  from  the  reaction  will  prolong  the  incendiary  action  upon 
inflammable  materials.  When  used  alone,  however,  it  has  the 
disadvantages  that  the  incendiary  action  is  confined  to  a  small 
area  and  that  the  heat  energy  is  wasted  because  of  the  fact  that 
it  is  so  rapid  in  its  action. 

For  this  reason  it  is  customary  to  add  a  highly  inflammable 
material,  which  will  become  ignited  by  the  thermit  and  will  con- 
tinue the  conflagration.  Petroleum  oils,  carbon  ■  disulfide,  wood 
distillation  products  and  other  inflammable  liquids  were  thor- 
oughly tested  for  this  purpose.  The  final  conclusion  was  reached 
that  oil,  solidified  with  soap  (sodium  salts  of  the  higher  fatty 
acids)  by  a  special  method  developed  by  the  Chemical  Warfare 
Service,  was  by  far  the  best  material  to  be  used.  In  certain  tests, 
using  a  combination  of  thermit  and  solid  oil,  flames  fifteen  feet 
high  were  obtained,  which  would  be  very  useful  against  walls, 
ceilings,  etc. 

336 


INCENDIARY  MATERIALS  337 

In  addition  to  this  type  of  incendiary  material,  it  was  desir- 
able to  have  a  spontaneously  inflammable  mixture  of  oils,  whicli 
could  be  used  in  Livens'  shell,  Stokes'  shell  or  aeroplane  bombs. 
The  basis  of  these  mixtures  is  fuel  oil  and  phosphorus.  By  vary- 
ing the  proportions  of  the  constituents  it  is  possible  to  obtain  a 
mixture  that  will  ignite  immediately  upon  exposure  to  the  air, 
or  one  that  will  have  a  delayed  action  of  from  30  seconds  to  two 
minutes. 

The  incorporation  of  metallic  sodium  gives  a  mixture  that 
will  ignite  when  spread  upon  water  surfaces. 

Incendiary  Devices 

The  incendiary  devices  used  during  the  Ikte  war  included 
bombs,    shell,    tracer    shell    and    bullets,    grenades,    and    flame 
throwers. 

Bombs 

Incendiary  bombs  were  used  almost  exclusively  by  aircraft. 
The  value  of  bombs  which  would  cause  destruction  by  starting 
conflagrations  was  early  recognized  but  their  development  was 
rather  slow.  "While  the  designs  were  constantly  changing,  two 
stand  out  as  the  most  favored :  a  small  unit,  such  as  the  Baby 
Incendiary  Bomb  of  the  English,  and  a  large  bomb,  such  as  the 
French  Chenard  bomb  or  the  American  Mark  II  bomb. 

In  general  bombs  which,  when  they  function  upon  impact, 
scatter  small  burning  units  over  a  considerable  area,  are  not 
favored.  Small  unit  bombs  can  be  more  effectively  used 
because  the  scatter  can  be  better  regulated  and  the  incendiary 
units  can  be  more  advantageously  placed. 
\  German  Bombs.  Incendiary  bombs  were  used  by  the  Ger- 
mans in  their  airplane  raids,  usually  in  connection  with  higli 
explosive  bombs.  A  typical  armament  of  the  later  series  of 
German  naval  airships  consisted  of  the  following: 

2  660-pound  bombs 
10  220-pound  bombs 
15  110-pound  bombs 
20  Incendiary  bombs 

making  a  total  weight  of  about  2^^  tons. 


338 


CHEMICAL  WARFARE 


A  typical  German  bomb  is  shown  in  Fig.  108.  It  consists 
essentially  of  a  receiver  of  white  iron  (r)  composed  of  a  casing 
and  a  central  tube  of  zinc,  joined  together  in  such  a  fashion 
that,  when  the  whole  was  complete,  it  had  the  appearance 
of  an  elongated  vessel  with  a  hollow  center.     Within  this 


Fig.  107  — Incendiary  Devices. 

(From  Left  to  Right).      Mark  II  Bomb,  B.  I.  Bomb,   Mark  I  Dart,  Mark  II  Dart, 
Mark  I  Dart,  Grenade,  Mark  I  Bomb. 


central  hollow  is  placed  a  priming  tube  (t)  of  thin  sheet  iron, 
pierced  by  a  number  of  circular  openings.  The  receiver  is 
about  445  mm.  (17.5  in.)  high  and  110  mm.  (4.3  in.)  at  its 
maximum  diameter.  It  is  wrapped  with  strands  of  tarred 
cord  over  nearly  its  entire  length.    The  empennage  (270  mm.  or 


INCENDIARY  MATERIALS 


339 


10.6  in. — in  height)  consisted  of  three  inclined  balancing  fins, 
which  assured  the  rotation  of  the  projectile  during  its  fall. 

In  the  body  of  the  bomb  was  a  viscous  mass  of  benzine 
hydrocarbons,  while  the  lower  part  of  the  receiver  contained 
a  mixture  of  potassium  perchlorate  and  paraffin.  The  central 
tube  apparently  contained  a  mixture  of  aluminum  and  sulfur. 

Later  the  Germans  used  a  scatter  type  of  bomb  (Fig.  109) 
which  was  designed  to  give  46  points  of  conflagration.    Each 


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Section  at  a  6 


All  DtmensionB  in  ICnUmeteri 

Fig.  108. — Aerial  Incendiary  Bomb, 
November,  1916. 


ning  Fuze 


Lighter 


Fig.  1C9. — German  Incendiary 
Bomb,  Scatter  Type. 


of  these  46  small  cylinders  contained  50  grams  of  an  air 
incendiary  material.  They  were  arranged  in  layers,  packed 
in  with  very  fine  gun  powder.  The  bomb  is  ignited  by  a  fric- 
tion lighter  which  is  pulled  automatically  when  the  bomb  is 
released  from  the  aeroplane.  The  bomb  is  constructed  to  burst 
in  the  air  and  not  on  striking  the  ground.  The  upper  part 
of  the  projectile  consists  of  a  cast  iron  nose  riveted  to  the 
sheet  iron  body  of  the  bomb.  When  the  explosion  occurs,  the 
nose  is  blown  away  and  the  small  incendiary  cylinders  are 
scattered  in  the  air.   . 


340  CHEMICAL  WARFARE 

The  incendiary  material  appears  to  be  a  mixture  of  barium 
nitrate  and  tar.  Its  incendiary  power  is  very  low  because 
combustion  takes  the  form  of  a  small  flame  of  very  short 
duration.  It  should,  however,  be  very .  valuable  for  firing 
inflammable  materials. 
[      British  Bombs.    The  early  British  bombs  were  petrol  bombs, 

Hwhich  were  used  without  great  success  for  crop  burning. 
Phosphorus  bombs  were  then  used  for  attacking  aircraft.  But 
the  most  successful  incendiary  is  the  so-called  ''Baby  Incen- 
diary Bomb."  This  is  a  6.5-ounce  bomb  with  an  incendiary 
charge  of  special  thermit.  These  small  bombs  are  car- 
ried in  containers  holding  either  144  or  272  bombs.  The 
former  container  approximates  in  size  and  weight  one  50-pound 
lI.E.  bomb  and  the  latter  one  120-pound  H.E.  bomb.  The  bomb 
contains  a  cartridge  very  much  like  a  shot  gun  shell  which, 
on  impact,  sets  down  on  the  striker  point  in  the  base  of  the 
body,  and  causes  the  ignition  of  the  charge.  It  is  claimed 
that  the  cartridge  of  the  B.I.  bomb  burns  when  totally  im- 
mersed in  any  liquid  (water  included)  and  in  depths  up  to 
two  feet  the  flame  breaks  through  the  surface. 

\l  French  Bombs.  The  French  used  three  types  of  incendiary 
ftombs,  a  special  thermit  (calonite),  the  Chenard  and  the 
Davidsen.  The  Chenard  bomb  is  a  true  intensive  type  and  is 
thought  to  be  very  successful.  It  functions  by  means  of  a 
time  fuse  operated  by  the  unscrewing  of  a  propeller,  before 
striking  the  ground,  and  reaches  its  target  in  flames.  Its 
chief  disadvantage  is  the  small  amount  of  incendiary  material 
which  it  carries.  The  Davidsen  bomb  expels  its  charge  as  a 
single  unit  and  is  not  considered  as  valuable  or  as  successful 
as  the  Chenard. 

K  [    American  Bombs.     The  program  of  the  Chemical  Warfare 
service  included  three  types  of  bombs: 

Mark  II  Incendiary  drop  bomb 
Mark  III  Incendiary  drop  bomb 
Mark     I  Scatter  bomb 

^  Mark  II  Bomb.  The  incendiary  Mark  II  drop  bomb  is 
designed  to  be  dropped  from  an  aeroplane  and  is  intended  for 
use  against  buildings,  etc.,  when  penetrating  effect  followed 
by  an  intensive  incendiary  action  is  sought. 


INCENDIARY  MATERIALS  341 

The  bomb  case  consists  of  two  parts:  a  body  and  a  nose. 
The  body  is  a  tapering  zinc  shell  which  carries  the  firing 
mechanism  and  stabilizing  tail  fin  at  the  small  end  and  at  the 
large  end  a  threaded  ring  which  screws  into  the  nose.  The 
nose  is  of  drawn  steel  of  such  shape  as  to  have  low  end-on 


.^^1^^  , 

1.--.^'      iaiitiirti,iii  ii  i  kri  .J  J! 

I  m 

h-lSb 

(■■Up  ,',•  iBw^     wim-'^-c^^ 

i«# 

'            ^  <  iifjjll^ 

IPM^^^n 

m' 

^/m                ^ww'             V^^^^*^^PI^      V 

f 

Fig.  110. — Loading  Bombs  with  "Solid"  Oil. 

resistance    and    is    sufficiently    strong    to    penetrate-    frame 
structures. 

The  incendiary  effect  is  produced  by  a  thermit  charge  car- 
ried in  the  nose  of  the  bomb.  This  charge  is  ignited  by  a 
booster  of  ''Thermit  Igniter"  fired  by  black  powder.  The 
latter  is  ignited  by  a  flash  from  the  discharge  of  a  standard 


342  CHEMICAL  WARFARE 

0.30  caliber  service  cartridge  contained  in  the  body  of  the  bomb, 
and  exploded  by  a  firing  mechanism  of  the  impact  type.  This 
method  of  firing  has  proven  wholly  unsatisfactory  and  will  be 
superseded  by  some  more  direct-acting  mechanism.  The  body 
of  the  bomb  is  filled  with  solidified  oil.  The  molten  thermit 
burns  through  the  case  of  the  bomb  and  liberates  the  oil  which 
has  been  partially  liquefied  by  the  heat  of  the  thermit  reaction. 
Additional  incendiary  effect  is  afforded  by  the  sodium  nitrate 
contained  in  the  nose  below  the  thermit,  and  by  two  sheet 
lead  cylinders  filled  with  sodium  and  imbedded  in  the  solid 
oil.  The  sodium  increases  the  difficulty  of  extinguishing  the 
fire  with  water. 

Mark  III  Bomb.  This  bomb  is  simply  a  larger  size  of  the 
Mark  II  bomb,  its  weight  being  approximately  100  pounds 
as  compared  with  40  pounds  for  the  Mark  II  bomb.  It  is 
designed  to  be  dropped  from  an  aeroplane  and  is  intended  for 
use  against  buildings  when  marked  penetrating  effect  is 
desired.  The  method  of  functioning  is  the  same  as  the  Mark 
II  bomb  and  it  has  the  same  defects  in  the  firing  mechanism. 
Mark  I  Bomb  (Scatter  Type).  The  Mark  I  incendiary  drop 
bomb  is  also  designed  to  be  dropped  from  aeroplanes  and  is 
intended  for  use  against  grain  fields,  ammunition  dumps,  light, 
structures  or  similar  objectives  when  only  a  low  degree  of 
ignition  is  required.  It  is  of  the  so-called  scatter  type,  due 
to  the  action  of  the  exploding  charge  which  casts  out  incen- 
diary material  within  a  radius  of  20  feet  from  the  point  of 
contact. 

The  incendiary  action  is  due  to  the  ejection  of  the  various 
incendiary  units  in  the  bomb  by  the  explosion  of  the  black 
powder  in  the  nose.  The  flash  of  this  explosion  serves  to 
ignite  the  units.  A  powder  charge  in  the  rear  of  the  bomb  acts 
simultaneously  with  the  nose  charge,  opening  the  bomb  casing, 
and  aiding  materially  in  the  scatter  of  the  units.  The  bomb 
is  so  arranged  as  to  function  close  to  the  ground,  which  is  a 
further  factor  in  the  scatter  of  the  units. 

The  incendiary  units  are  waste  balls  about  2.5  in.  in  diameter 
and  having  an  average  weight  of  2.5  ounces,  tied  securely 
with  strong  twine.  These  are  soaked  in  a  special  oil  mixture. 
Carbon  disulfide   and  crude  turpentine,   or  carbon  disulfide, 


INCENDIARY    MATERIALS  343 

benzene  heads  and  crude  kerosene  gave  satisfactory  results. 
A  later  development  attempted  to  replace  the  waste  balls  by 
solid  oil,  but  the  difficulties  of  manufacture  and  questions  of 
transportation  argued  against  its  adoption. 

These  bombs  were  not  used  at  the  front.  Nearly  all  of 
the  American  incendiary  bombs  proved  too  light  on  the  nose 
and  lower  half,  generally  resulting  in  deformation  upon  impact 
and  very  poor  results.    New  ones  will  be  made  stronger. 


Incendiary  Darts      \j 

The  British  early  recognized  the  value  of  a  small  bomb, 
and  consequently  adopted  their  B.I.B.  (Baby  Incendiary 
Bomb),  weighing  about  6.5  ounces.  These  are  capable  of  being 
dropped  in  lots  of  100  or  more  and  thus  literally  shower  a 
given  territory  with  fire.  The  intensity  of  fire  at  any  given 
point  is  much  less  than  that  obtained  with  the  larger  bombs, 
but  the  increased  area  under  bombardment  more  than  counter- 
balances this  disadvantage.  While  the  British  aimed  at  the 
perfection  of  a  universal  bomb,  the  American  service  felt  that 
two  classes  should  be  developed,  one  to  be  used  against  grain 
fields  and  forests,  the  other  against  buildings. 

The  first  class  was  called  the  Mark  I  Dart.  This  consisted 
of  an  elongated  12-gauge  shot  gun  shell,  filled  with  incendiary 
material  and  provided  with  a  firing  mechanism  lo  ignite  the 
primer  as  the  dart  strikes  the  ground.  The  flash  of  the  primer 
sets  fire  to  the  booster,  which,  in  turn,  ignites  the  main  incen- 
diary charge.  The  latter  burns  several  minutes,  with  a  long 
flame.  A  retarding  stabilizer  attached  to  the  tail  of  the  dart 
serves  the  two-fold  purpose  of  insuring  the  functioning  of 
the  flring  mechanism  and,  by  retarding  the  final  velocity  of 
the  dart,  preventing  the  collapse  of  the  dart  body  when 
dropped  from  very  high  altitudes. 

The  incendiary  mixture  is  one  which  gives  a  long  hot  flame, 
burns  for  several  minutes  and  leaves  very  little  ash.  In  general 
it  consists  of  an  oxidizing  agent  (barium  or  sodium  chlorate), 
a  reducing  agent  (aluminum,  or  a  mixture  of  iron,  aluminum 
and  magnesium),  a  filler  (rosin,  powdered  asphaltum  or  naph- 
thalene) and  in  some  cases  a  binder  (asphaltum,  varnish  or 
boiled  linseed  oil). 


344  CHEMICAL  WARFARE 

The  Mark  II  Dart  was  developed  to  furnish  a  small  size 
penetrating  agent.  It  consists  of  a  two-inch  (diameter)  zinc 
case  filled  withlhermit  and  solid  oil  as  the  incendiary  materials 
and  provided  with  a  cast  iron  nose  for  penetration.  During 
the  first  half  minute-  after  firing,  a  pool  of  molten  iron  is 
formed  by  the  thermit,  which  is  very  penetrating  and  affords 
a  good  combustible  surface  for  the  oil,  which  burns  for  an 
additional  ten  minutes. 

It  has  an  advantage  over  the  Mark  I  dart  in  that  it  pene- 
trates, and  over  the  Mark  II  bomb  in  that  it  is  smaller  and 
lighter  in  weight. 

Incendiary  Shell 

Incendiary  shell  have  been  successfully/  used  against  ai^^ 
craft  and  to  some  extent  in  bombardments  of  inflammable 
ground  targets.  Anti-aircraft  shell  are  of  small  caliber  and 
are  usually  tracer-incendiary.  Such  shell  are  filled  with 
pyrotechnic  mixtures  which  ignite  at  the  moment  of  firing, 
or  by  time  fuse,  and  are  effective  against  highly  inflammable 
material.  Shell  filled  with  thermit  which  explode  and  scatter 
the  molten  iron  have  been  used  against  aircraft  and  ground 
targets,  but  with  rather  poor  results.  Large  shell,  which  burst 
upon  impact  and  scatter  units  of  burning  materials,  have  been 
used  with  some  success  against  ground  targets. 

Tracer  shell  contain  such  mixtures  as  barium  nitrate,  mag- 
nesium and  shellac,  or  red  lead  and  magnesium. 

Incendiary  Bullets  "\  \ 

Incendiary  bullets  are  only  effective  against  highly  inflam- 
mable material,  and  are  therefore  used  principally  in  aerial 
warfare  against  aircraft,  either  for  the  purpose  of  igniting  the 
hydrogen  of  the  gas  bag,  or  the  gasoline.  The  present  tendency 
is  towards  the  use  of  the  large  size  (11  mm.)  bullet,  because 
of  its  greater  incendiary  action. 

The  incendiary  material  is  either  white  phosphorus  or  a 
special  incendiary  mixture  consisting  of  an  oxidizing  agent 
and  some  combustible  or  mixture  of  combustibles.     The  white 


INCENDIARY  MATERIALS  345 

tracer  bullet  contains  a  mixture  of  barium  peroxide  and  mag- 
nesium. A  red  bullet  contained  in  addition,  strontium  nitrate 
and  chloride,  or  peroxide. 

Incendiary  Hand  Grenade    \f 

While  the  use  of  incendiary  grenades  and  oth|fer  small  incen- 
diary devices  is  limited,  sucli  armament  is  considered  very 
valuable  in  trench  warfare.  They  can  be  used  to  set  fire  to 
inflammable  material,  either  in  offensive  or  defensive  opera- 
tions. 

Phosphorus  grenades,  while  used  principally  for  producing 
smoke  (see  page  302),  have  considerable  value  as  an  incendiary 
weapon. 

Thermit  grenades  are  very  useful  in  rendering  unserviceable 
guns  and  other  metallic  equipment  which  must  be  abandoned. 
They  permit  aviators  to  destroy  planes  which  motor  troubles 
oblige  to  land  in  enemy  territory.  They  are  also  used  to  ignite 
inflammable  liquids,  thrown  into  a  dugout,  or  sprayed  over  an 
objective  by  a  flame  projector. 

The  Mark  I  hand  grenade  was  developed  for  burning  enemy 
ammunition  dumps,  for  clearing  away  brush  or  other  material 
in  front  of  trenches  and  for  use  in  dugouts.  The  standard 
n.E.  grenade  body  was  half-filled  with  thermit  and  half  with 
a  celluloid  container  filled  with  a  solidified  fuel  oil.  The 
grenade  is  fired  by  the  spit  of  the  fuse  of  the  bouchon  firing 
mechanism.  This,  through  the  booster,  lights  the  thermit 
igniter,  which  in  turn  fires  the  main  charge  of  thermit.  The 
resulting  molten  iron  readily  penetrates  the  grenade  case,  at 
the  same  time  igniting  the  celluloid  case  and  its  contents.  The 
oil  burns  for  about  3.5  minutes.  This  grenade  was  never  used 
since  it  was  considered  that  an  all  thermit  grenade  would  be 
of  more  value. 


Trench  Mortar  Equipment 

Special  projectiles  were  designed  for  use  witli  the  Stokes 
mortar  and  the  Livens'  projector.  Thermit  was  used  only 
in  Stokes'  projectiles.     The  Livens'  projectile  was  filled  with 


346 


CHEMICAL  WARFARE 


inflammable  units  (chlorated  jute)  immersed  in  a  light  oil 
mixture.  Thrown  from  a  projector  into  the  enemy's  trench, 
it  explodes,  giving  a  large  flash  and  scattering  the  burning 
units  over  an  area  of  forty  yards.  The  Mark  II  projectile, 
designed  for  general  incendiary  effect  against  readily  inflam- 
mable material,  consists  of  an  altered  8-inch  Livens'  gas  projec- 
tile filled  with  chlorated  jute  units  impregnated  with  solid  oil 


Mild  Steel-Copper  Plated 
Inside  and  Out 


White  FhoaporuB 


Bed  Varnish 

725 > 

Fig,  111. — German  8"  Ircendiary  Bullet. 


r 


'Lead 


Small  Glass 
Bulb  Filled  with 
-Sulphuric  Acid 


-Kolled  Tin-Foil 
-2.8 


jCelluloid  Tube 

Filled  with 

Potassium 

Chlorate 

—Cork  Plug 
-Lead 


Fig.  112. — German  Incen- 
diary Blue  Pencil. 


and  immersed  in  a  spontaneously  inflammable  oil.  After  a  short 
delay,  these  units  burst  into  flame  and  burn  vigorously  for 
several  minutes.  It  is  almost  impossible  to  extinguish  them 
without  large  quantities  of  water.  Such  bombs  have  only  a 
very  limited  use,  so  that  it  is  questionable  if  they  are  really 
worth  while. 


German  Blue  Pencil 


v\ 


A  very  interesting  and  curious  device  was  developed  by 
the  Germans  in  the  form  of  an  incendiary  pencil.     Similar  in 


INCENDIARY  MATERIALS  347 

appearance  to  a  common  blue  pencil,  sharpened  at  one  end, 
they  are  distinguished  only  by  a  small,  almost  imperceptible, 
point  placed  on  the  outside  11  mm.  from  the  unsharpened 
end.  They  are  175  mm.  long,  11.1  mm.  in  diameter  and  weigh 
12  to  13  grams.  The  interior  of  the  pencil  contains  a  glass 
Inilb,  with  two  compartments  filled  with  sulfuric  acid  and 
I  celluloid  tube  filled  with  potassium  chlorate.  The  glass  bulb 
ends  in  a  slender  point;  when  this  is  broken  the  acid  comes 
into  contact  with  the  chlorate  and  causes  an  explosion.  The 
two  materials  are  separated  by  a  layer  of  clay,  which  causes 
a  delayed  action  of  about  30  minutes.  The  operator  breaks 
the  point  of  bulb,  buries  the  pencil  vertically  in  the  inflam- 
mable material  and  then  has  half  an  hour  in  which  to  got 
away,  before  any  possibility  of  a  fire.  He  cuts  the  pencil 
with  a  knife  2  cm.  from  the  point,  so  that  if  caught  he  has 
the  appearance  of  simply  sharpening  a  pencil. 


Flaming  Gun        \ 

Among  the  unsuccessful  weapons  of  the  late  war,  the  liquid 
fire  gun  or  Flammenwerfer,  as  the  German  called  it,  is  prob- 
ably the  most  interesting.  Its  origin,  according  to  a  German 
story,  was  due  to  a  mere  accident.  A  certain  officer,  during 
peace  maneuvers,  was  ordered  to  hold  a  fort  at  all  cost.  During 
the  sham  fight,  having  employed  all  the  means  at  his  disposal, 
he  finally  called  out  the  fire  brigade  and  directed  streams 
of  water  upon  the  attacking  force.  Afterwards,  during  the 
criticism  of  the  operations  in  the  presence  of  the  Kaiser,  he 
claimed  that  he  had  subjected  the  attackers  to  streams  of 
burning  oil.  The  Kaiser  immediately  inquired  whether  such 
a  thing  would  be  possible,  and  was  assured  that  it  was  entirely 
feasible. 

Long  series  of  experiments  were  necessary  before  a  satis- 
factory combination  of  oils  was  produced,  which  could  be 
projected  as  a  flame  on  the  enemy,  but  they  were  finally  suc- 
cessful. Unlike  the  use  of  poison  gas,  however,  the  flaming 
liquid  gun  did  not  prove  to  be  a  successful  weapon  of  warfare. 
True,  at  first  they  were  rather  successful,  but  this  was  before 
the  men  learned  their  real  nature.     In  the  first  attack,  the 


348 


CHEMICAL  WARFARE 


Allies  were  completely  surprised  and  the  troops  were  routed 
by  the  flames.  Auld  tells  of  one  of  the  early  attacks  (July  29, 
1915)  when,  without  warning,  the  front  line  troops  were 
enveloped  in  ilames.     Where  the  flames  came  from  could  not 


be  seen.  All  that  the  men  knew  was  that  they  seemed  sur- 
rounded by  fierce,  curling  flames,  which  were  accompanied 
by  a  loud  roaring  noise,  and  dense  clouds  of  black  smoke. 
Here  and  there  a  big  blob  of  burning  oil  would  fall  into  a 
trench  or  saphead.    Shouts  and  yells  rent  the  air  as  individual 


INCENDIARY    MATERIALS  349 

men,  rising  up  in  the  trenches  or  attempting  to  move  in  the 
open,  felt  the  force  of  the  flames.  The  only  way  to  safety 
appeared  to  be  to  the  rear.  This  direction  the  men  that  were 
left  took.  For  a  short  space  the  flames  pursued  them  and  the 
local  retirement  became  a  local  rout.  After  the  bombardment 
which  followed,  only  one  man  is  known  to  have  returned. 

After  a  study  of  the  pictures  of  the  liquid  fire  gun  in 
operation,  it  is  evident  that  the  men  could  not  be  blamed  for 
tliis  retirement.  One  has  only  to  imagine  being  faced  by  a 
sjHTad  of  flame  similar  to  that  used  for  the  oil  burners  under 
the  largest  boiler,  but  with  a  jet  nearly  60  feet  in  length 
and  capable  of  being  sprayed  round  as  one  might  spray  water 
v/ith  a  fire  hose. 

Later,  when  the  device  was  better  known  it  was  different, 
though  even  then  it  was  a  pretty  good  test  of  a  man's  nerve. 
It  was  found  that  the  flames  could  not  follow  one  to  the 
bottom  of  a  trench  as  the  gas  did,  and  that,  if  a  man  crouched 
to  the  bottom  of  his  trench,  his  head  might  be  very  warm  for 
a  minute  or  so  but  that  the  danger  was  soon  past  and  he  then 
could  pick  off  the  man  who  had  so  recently  made  things 
uncomfortable  for  him. 

While  it  is  said  that  Major  R.,  who  invented  the  Flammen- 
werfer,  enjoyed  a  great  popularity  among  his  men,  and  is 
familiarly  known  as  the  Prince  of  Hades,  there  is  no  doubt 
that  this  was  not  shared  by  the  Allies.  Their  rule  was:  ** Shoot 
the  man  carrying  the  apparatus  before  he  gets  in  his  shot,  if 
possible.  If  this  cannot  be  done,  take  cover  from  the  flames 
and  shoot  him  afterwards." 

The  German  had  several  types,  which  may  be  grouped  into 
the  small  or  portable  and  the  krgre  Flammenwerfers. 

The  portable  Flammenwerfer  consisted  of  a  sheet  steel 
cylinder  of  two  compartments,  one  to  hold  compressed 
nitrogen,  the  other  to  hold  the  oil.  The  nitrogen  furnished  the 
pressure  which  forces  the  oil  out  through  the  flexible  tube. 
Air  cannot  be  used,  because  the  oxygen  would  form  an  explo- 
sive mixture  with  the  vapors  of  the  oil,  and  any  heating  on 
compression,  or  back  flash  from  the  flame  or  fuse  might  make 
things  very  unpleasant  for  the  operator.  A  pressure  of  about 
23  atmospheres  is  reached  when  the  cylinder  is  charged.    The 


350 


CHEMICAL  WARFARE 


nitrogen  appeared  to  be  carried  on  the  field  in  large  containers 
and  the  flame  projectors  actually  charged  in  the  trenches. 

The  oil  used  in  the  flame  projectors  varied  from  time  to 
time,  but  always  contained  a  mixture  of  light  or  easily  volatile 
and  heavy  and  less  volatile  fractions  of  petroleum  or  mineral 
oil,  very  carefully  mixed.  In  some  cases  even  ordinary  com- 
mercial ether  has  been  found  in  the  cylinders. 

The  most  interesting  part  about  the  flame  projector  is  the 
lighting  device.     This  is  so  made  that  the  oil  ignites  spon- 


FiG.  114. — Small  Flammenwerfer. 

taneously  the  minute  the  jet  is  turned  on,  and  is  kept  alight 
by  a  fiercely  burning  mixture  which  lasts  throughout  the 
discharge.  This  mixture  is  composed  of  barium  nitrate,  potas- 
sium nitrate,  metallic  magnesium  and  charcoal,  with  some 
resinous  material.  The  priming  consists  of  black  powder  and 
metallic  magnesium. 

When  the  oil  rushes  out  of  the  jet,  it  forces  up  the  plunger 
of  a  friction  lighter  and  ignites  this  core  of  fiercely  burning 
mixture. 


INCENDIARY  MATERIALS 


351 


The  range  of  these  small  projectors  is  from  14  to  17  meters 
(17  to  20  yards)  but  the  duration  of  the  flame  is  rather  less 
than  a  minute. 

In  a  later  pattern,  it  was  designed  that  one  nozzle  should 
be  issued  to  three  reservoirs.  After  the  discharge  of  one,  the 
jet  is  attached  to  the  others  in  succession.  This  is  called  the 
*'Wx"  Flammenwerfer  (interchangeable).  In  this  way  a 
squad  of  three  men  could  carry  58  pints  of  inflammable  oil. 
It  is  a  question,  though,  whether  the  third  man  would  live 
to  use  his  reservoir. 


6age 


"^.i.        I 

*♦ 


Htjdroqe 


hkjdro^en  Ignition; >-''      , 


Fig.  115. — Boyd  Flame  Projector. 

The  fact  that  the  trenches  were  often  very  close  together 
during  the  early  part  of  the  war,  made  possible  the  use  of 
large  or  stationary  Flammenwerfer.  These  consisted  of  a  steel 
reservoir  SVg  feet  in  height  and  l^/g  feet  in  diameter,  weighing 
about  250  pounds,  which  could  be  connected  to  two  steel 
cylinders,  containing  nitrogen  under  pressure.  These  carried 
180  liters  (40  gallons)  of  liquid  and  operated  under  a  pressure 
of  15  atmospheres.  The  discharge  nozzle  was  at  the  end  of 
a  metal  tube  three  feet  long,  and  its  orifice  was  about  Vig 
of  an  inch  in  diameter.     The  range  of  this  apparatus  was 


352  CHEMICAL  WARFARE 

from  33  to  40  yards  and  the  duration  of  the  flame  from  one 
to  two  minutes.  Because  of  the  comparatively  short  range 
of  these  guns  and  the  ease  with  which  they  could  be  destroyed, 
if  located  by  the  enemy,  their  use  was  very  limited. 

Even  with  the  portable  flammenwerfer,  the  most  difficult 
thing  to  do  is  to  get  near  enough  the  target  to  make  the 
shoot  effective.  Another  serious  disadvantage  is  its  very  short 
duration.  It  is  impossible  to  charge  up  again  on  the  spot, 
and  the  result  is  that  once  the  flame  stops,  the  whole  game 
is  finished  and  the  operators  are  at  the  mercy  of  the  enemy. 

With  these  facts  in  mind  it  is  easy  to  see  how  service 
in  the  flaming  gun  regiments  is  apparently  a  form  of  punish- 
ment. Men  convicted  of  offenses  in  other  regiments  were 
transferred  cither  for  a  time  or  permanently  and  were  forced 
under  threat  of  death  in  the  most  hazardous  enterprises  and 
to  carry  out  the  most  dangerous  work.  Taken  all  in  all  the 
flame  thrower  was  one  of  the  greatest  failures  among  the  many 
promising  devices  tried  out  on  a  large  scale  in  the  war. 


chaptp:r  XXI 

THE  PHARMACOLOGY  OF  WAR  GASES 

The  pharmacology  of  war  gases  plays  such  an  important 
part  in  chemical  warfare  that  a  brief  discussion  may  well  be 
given  of  the  methods  used  in  the  testing  of  gases  for  toxicity 
and  other  pharmacological  properties. 

War  gases  may  be  divided  into  two  groups:  persistent  and 
non-persistent,  each  of  which  may  include  several  classes: 

I.  Lethal 

II.  Lachrymatory 

III.  Sternutatory 

IV.  Special 

PJach  class  necessitates   special  tests   in   order  to   determine 
whether  or  not  it  is  suitable  for  further  development. 

,  Toxicity 

One  of  the  first  paints  which  must  be  carefully  determined 
in  investigating  a  substance  is  its  toxicity.  It  is  important 
that  this  be  determined  for  numerous  reasons: 

1.  To  determine  what  concentrations  are  dangerous  in  the 
field. 

2.  To  ascertain  how  effective  protective  devices  have  to 
be  to  furnish  sufficient  protection  against  the  gas. 

3.  To  furnish  a  basis  for  accurate  experimental  work  on  tlid 
treatment  of  gassed  cases. 

4.  To  decide  whether  or  not  the  material  is  worthy  of  further 
development  in  the  laboratory  or  in  the  plant. 

These  considerations  necessitate  the  determination  of  the 
toxicity  in  the  form  of  a  vapor  and  not  by  the  ordinary  method 
of  administration  by  mouth,  through  the  skin  (subcutaneously) 
or  through  the  blood  (intravenously).  The  simplest  method  of 
determining  the  toxicity  of  a  substance  as  a  vapor  would  be 
to  place  animals  in  a  gas-tight  box  and  introduce  a  known 
amount  of  the  substance  in  the  form  of  vapor.     But  by  this 

353 


354 


CHEMICAL  WARFARE 


method  the  concentration  is  not  accurately  known  unless  chemical 
analyses  of  the  air  are  made,  and  then  it  is  found  to  be  much 
less  than  that  calculated  from  the  amount  of  substance  intro- 
duced, because  of  condensation  on  the  walls  of  the  chamber,  or 
absorption  of  the  substance  by  the  skin  and  hair  of  the  animal 
and  in  some  cases,  of  decomposition  of  the  substance  by  moisture 
in  the  air.  Moreover,  it  is  found  that  the  concentration  decreases 
markedly  with  time.  Because  of  these  factors,  the  figures  used 
for  the  concentration  are  more  or  less  guess  work.  To  overcome 
these  difficulties,  a  chamber  is  used  through  which  a  continuous 
current  of  air,  containing  a  known  and  constant  amount  of  the 


k€> 


Fig.  116. — Continuous  Flow  Gassing  Chamber  for  Animals. 

poisonous  vapor,  is  passed.  Such  an  apparatus  is  shown  in 
Fig.  116. 

The  flask  ^  is  a  300  cc.  Erlenmeyer  flask,  with  a  ground  glass 
stopper.  The  liquid  to  be  tested  is  placed  in  this  flask  together 
with  a  sufficient  quantity  of  glass  wool  to  prevent  splashing  and 
the  carrying  over  mechanically  of  droplets  of  the  liquid.  Air  is 
passed  through  A  and  C  (calcium  chloride  drying  tubes)  and 
the  rate  measured  by  the  flow  meter  D.  The  air  and  gas  are 
mixed  in  F  before  passing  into  the  chamber  G.  This  chamber  is 
made  of  plate  glass,  is  of  about  100  liters  capacity,  and  is  air- 
tight. The  entire  flow  of  air  and  gas  through  the  box,  kept 
constant  at  250  liters  per  minute,  is  measured  at  H.  The  gas  is 
removed  through  K,  which  is  filled  with  charcoal  and  soda  lime, 
in  order  that  little  gas  may  pass  into  the  pump. 

By  weighing  the  flask  E,  and  its  contents  before  and  after 
passing  air  through  it,  and  knowing  the  total  volume  of  the 


THE  PHARMACOLOGY  OF  WAR  GASES  355 

mixture  passing  through  the  chamber  during  the  same  period, 
the  concentration  of  the  substance  can  readily  be  calculated. 
This  concentration,  as  determined  by  the  "loss  in  weight" 
method,  can  be  checked  by  chemical  analysis  (samples  taken  at 
M — M).    The  method  has  been  found  to  give  accurate  values. 

The  concentration  in  the  chamber  reaches  its  constant  level 
within  30  to  40  seconds  after  the  apparatus  is  started. 

With  the  flow  of  250  liters  per  minute,  the  difficulties  men- 
tioned above  are  reduced  to  a  point  where  they  are  practically 
negligible. 

All  toxicity  tests  on  mice  were  made  with  an  exposure  of  ten 
minutes,  while  dogs  were  exposed  for  thirty  minutes.  In  case 
death  did  not  occur  during  exposure,  the  animals  were  kept 
under  observation  for  several  days.  Toxicity  and  all  other 
figures  are  expressed  in  milligrams  per  liter  of  air,  though  parts 
per  million  (p.p.m.)  was  frequently  used  during  the  early 
work. 

Another  point  of  difficulty  is  the  great  individual  variation 
in  the  susceptibility  of  animals.  This  is  probably  greater  than 
when  the  poison  is  administered  subcutaneously  or  intravenously. 
It  necessitates  the  use  of  a  large  number  of  animals  in  making  a 
determination  of  the  toxicity  of  a  gas.  Again,  the  toxicity  for 
different  species  may  vary,  and  as  the  ultimate  aim  is  a  knowl- 
edge of  the  toxicity  for  man,  a  great  many  different  species  must 
be  used.  If  the  toxicity  is  widely  different  for  different  animal 
species,  it  is  hard  to  arrive  at  a  definite  conclusion  as  to  the 
toxicity  for  man. 

With  longer  exposures  than  thirty  minutes  the  lethal  con- 
centration is  usually  less,  there  being  a  cumulative  effect.  This 
is  not  true  for  hydrocyanic  acid.  If  the  concentration  is  not 
enough  to  kill  at  once,  an  animal  can  stand  it  almost  indefinitely. 
Whether  the  action  is  cumulative  or  not  depends  on  the  rate  at 
which  the  system  destroys  or  eliminates  the  poison.  If  the 
poison  is  being  eliminated  as  fast  as  received  the  concentration 
in  the  tissues  cannot  increase.  It  is  stated,  for  example,  that 
the  amount  of  nicotine  in  a  cigar  would  kill  a  man  if  taken  in 
one  dose.  If  it  is  spread  over  twenty  minutes,  the  destruction  or 
elimination  of  the  nicotine  is  so  rapid  that  no  obviously  bad 
effects  are  noted. 

Another  interesting  thing  about  the  work  on  poison  gases  is 


!53 


CHEMICAL  WARFARE 


that  in  most  cases  a  preliminary  exposure  to  less  than  the  lethal 
concentidtion  does  not  seem  to  make  the  animal  either  more  or 
less  sensitive  on  a  later  exposure.  This  is  quite  unexpected,  be- 
cause we  know  that  with  irritating  gases,  especially  lachrymators, 
men  adapt  themselves  to  much  higher  concentrations  than  they 
could  stand  at  first.  In  view  of  the  experiences  of  arsenic 
eaters,  it  is  quite  possible  that  the  experiments,  which  showed  no 
accustoming  to  toxic  gases,  were  not  continued  long  enough  to 
give  positive  results. 

Not  only  does  the  susceptibility  of  different  animals  of  the 


Air  Intake 


Dry  Filtered  ^ir 
under  Pressure 


f°SF 


l/m 


ELEVATION 
Aeration  Apparatus    jj  J 

Not  drawn  to  Scale 

HI 


^F 


Fig.  117. 


Bg    PLAN  DF  E 
-Aeration  Apparatus  for  Testing  Lachrymators. 


same  species  vary  greatly  for  a  particular  gas,  but  the  suscep- 
tibility of  different  species  varies  greatly  with  different  gases. 
Thus  while  the  effects  of  certain  gases  on  mice  are  quite  com- 
parable to  the  effects  on  man,  it  is  very  far  from  being  true  with 
other  gases. 

Lachrymators 

While  one  cannot  determine  the  lethal  concentrations  of 
poison  gases  for  men,  it  is  possible  to  determine  the  concentration 
that  will  produce  lachrymation.  The  threshold  value  is  that  at 
which  two-thirds  of  the  observers  experience  irritation.  The 
lachrymatory  value  is  considerably  higher  than  the  threshold 
value. 

A  very  satisfactory  method  for  determining  lachrymatory 
values  is  shown  in  Fig.  117.  Air  is  measured  at  A  and 
bubbled  through  the  lachrymatory  substance  in  B.     The  air  and 


THE  PHARMACOLOGY  OF  WAR  GASES 


357 


gas  are  mixed  in  D  and  pass  into  E,  a  gas-tight,  glass-walled 
chamber  of  about  150  liters  capacity.  The  gas  is  removed 
through  Ef,  by  suction  and  the  volume  of  the  air-gas  mixture 
measured  by  the  flow  meter,  F. 

After  the  apparatus  has  run  a  few  minutes,  and  the  con- 
centration of  the  gas  has  become  constant,  the  subject  is 
instructed  to  adjust  the  mask,  attached  at  H,  and  to  tell  what- 


M: 


Air  Pressure 

FRENCH  SPRAY 

Not  to  Scale 


Approz.FulI  Size 


SIDE  ELEVATION 
Not  to  Scale 


END  ELEVATION 


Approx.Full  Size 


Fig.  118.— Type  of  Spray  Nozzles. 

ever  he  notices  just  as  soon  as  he  notices  it.  The  operator 
stands  in  such  a  position  that  he  can  manipulate  the  stopcock  H 
without  being  observed  by  the  subject.  After  breathing  air  for 
a  time  (il  is  a  two-way  cock,  connected  with  the  air  through  J, 
and  to  the  chamber  through  Eg)  both  to  become  accustomed 
to  the  mask  and  to  eliminate,  as  far  as  possible,  any  "psycho- 
logical symptoms,"  the  subject  is  allowed  to  breathe  the  gas 
mixture  for  a  maximum  of  three  minutes.  If  the  expected  symp- 
toms are  produced  in  less  than  this  time,  the  test  is  discontinued 
as  soon  as  they  develop. 


358  CHEMICAL  WARFARE 

For  accurate  work,  it  is  necessary  to  work  with  a  pure  sample 
which  is  at  least  fairly  volatile.  Mixtures  cannot  be  run  by  this 
method.  In  this  case  it  is  necessary  to  volatilize  each  separately, 
passing  the  vapors  simultaneously  into  the  mixing  chamber  E. 

A  spray  method  may  also  be  used  with  satisfactory  results. 
Types  of  sprays  are  shown  in  Fig.  118. 

Odors 

Because  of  the  great  value  in  detecting  low  concentrations 
of  gases  in  the  field,  it  is  important  to  know  the  smallest  amount 
of  a  gas  that  can  be  detected  by  odor.  In  some  cases,  this  test  is 
more  delicate  than  any  chemical  test  yet  devised. 

Odors  may  be  divided  into  two  classes,  true  odors,  and  mild 
irritation.  By  true  odor  is  meant  a  definite  stimulation  of  the 
olfactory  nerve,  giving  rise  to  a  sensation  which  is  more  or  less 
characteristic  for  each  substance  producing  the  stimulation. 
Mild  irritation  defines  the  sensation  which  is  confused  with  the 
sense  of  smell  by  untrained  observers,  but  which  is  really  a  gentle 
stimulation  of  the  sensory  nerve  endings  of  the  nose.  This  so- 
called  odor  of  substances  producing  this  effect  is  not  character- 
istic. Higher  concentrations  of  these  compounds  almost  in- 
variably cause  a  definite  irritation  of  the  nose. 

Examples  of  true  odors  are  the  mercaptans,  mustard  gas, 
bromoacetone,  acrolein,  chlorine  and  ammonia.  Substances 
which  cause  mild  irritation  are  chloroacetone,  methyl  dichloro- 
arsine,  ethyl  iodoacetate  and  chloropicrin. 

In  making  the  test  for  odor,  the  same  apparatus  is  used  as  for 
lachrymators.  The  time  of  exposure  is  shortened  to  30  seconds, 
as  the  subject  always  detects  the  odor  at  the  first  or  second  in- 
halation. 

In  this  connection  the  recent  work  of  Allison  and  Katz  (J. 
Ind.  Eng.'Chem.  11,  336,  (1919))  is  of  interest.  They  have  de- 
signed an  instrument,  **the  odorometer, '  *  for  measuring  the  in- 
tensity of  odors  in  varying  concentrations  in  air.  It  is  based  on 
the  principle  given  above.  A  measured  volume  of  air  is  passed 
through  the  liquid  and  then  diluted  to  a  given  concentration. 
The  mixture  is  then  passed  through  a  rubber  tube  with  a  glass 
funnel  at  the  open  end.    Only  one  inhalation  of  the  mixture  is 


THE  PHARMACOLOGY  OF  WAR  GASES  359 

used  to  determine  the  intensity  of  the  odor.  The  position  of  any 
strength  of  odor  on  the  scale  depends  upon  the  sensitiveness  and 
judgment  of  the  operator,  but  with  one  person  conducting  the 
entire  test,  the  results  have  been  found  quite  satisfactory.  (See 
tables  on  pages  360  and  361.) 

Skin  Irritants 

Substances  which  seem  useful  for  producing  skin  burns  are 
studied  both  on  animals  and  on  man.  Dichloroethyl  sulfide 
(mustard  gas)  is  used  as  a  basis  of  comparison.  Several  methods 
are  available. 

Direct  Application.  This  method  consists  of  the  direct 
application  of  the  compound  itself  to  the  skin,  using  a  definite 
quantity  (0.005  cc.  or  0.005  mg.)  over  a  definite  area  (5  square 
centimeters)  of  the  skin.  With  such  a  quantity  of  mustard  gas 
a  rather  severe  burn  on  animals  is  produced.  No  precautions 
are  taken  to  prevent  evaporation  from  the  skin  since  it  is 
believed  that  in  this  way  the  test  will  approximate  fairly  closely 
the  field  conditions. 

Vapor  Tests.  Preliminary  tests  with  vapors  of  volatile 
compounds  are  best  made  by  placing  a  small  amount  of  the 
material  on  a  plug  of  cotton  in  the  bottom  of  a  test  tube  enclosed 
in  a  larger  test  tube  which  acts  as  an  air  jacket.  After  about  an 
hour  at  room  temperature  the  mouth  of  the  test  tube  is  applied 
to  the  skin.  The  concentration  is  not  known,  but  one  is  dealing 
practically  with  saturated  vapor.  If  an  exposure  of  from  30  to 
60  minutes  produces  no  effect,  one  is  safe  to  assume  that  the 
compound  is  not  sufficiently  active  to  be  of  value  as  a  skin 
irritant. 

If  quantitative  results  are  desired,  the  apparatus  shown  in 
Fig.  119  is  used.  Dry  air  is  blown  through  the  bubbler,  which 
is  connected  with  a  series  of  glass  skin  applicators. '  The  con- 
centration is  determined  in  the  usual  way.  The  skin  applicator 
consists  of  a  small  cylinder  about  1.5  to  2  cm.  in  diameter  and 
about  4  cm.  long  with  a  small  glass  handle  attached  on  top. 
The  opening  is  1  cm.  in  diameter.  "When  the  concentration  of 
the  gas  is  constant,  the  exposure  to  the  skin  is  made  directly 
for  ^ny  desired  length  of  time.    The  skin  irritant  efficiency  is 


360 


CHEMICAL  WARFARE 


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THE  PHARMACOLOGY  OF  WAR  GASES 


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362 


CHEMICAL  WARFARE 


judged  by  comparing  the  per  cent  of  positive  responses  to 
approximately  equal  concentrations  of  the  vapors,  using  mus- 
tard gas  as  a  standard. 

Touch  Method.     This  method  consists  of  dipping  a  small 
glass  rod  drawn  to  a  needle-like  end  to  the  depth  of  1  mm. 


Ait  Pressure 


A  To  be  Corked  when 

not  in  use. 

Applied  to  Skin  when 

iu  use. 


Absorption 
for  Analysis 


Fig.  119. — Skin  Irritant  Vapor  Apparatus. 


in  the  compound  and  then  quickly  touching  the   skin.     The 
method  is  qualitative  only. 

Use  of  Solutions.  Alcohol,  kerosene,  olive  oil,  carbon 
tetrachloride  and  other  solvents  may  be  used  for  the  purpose  of 
determining  the  lowest  effective  concentration  of  a  substance, 
and  for  the  determination  of  the  relative  skin  irritant  efficiencies 
of  various  compounds.  Since  the  skin  irritants  were  scarcely 
ever  used  in  this  form  in  the  field,  that  is,  in  solution,  the 
method  is  not  as  satisfactory  as  the  vapor  method. 


CHAPTER  XXII 

CHEMICAL  WARFARE  IN  RELATION  TO  STRATEGY 
AND  TACTICS  ^ 

Fundamentals  of  War.  The  underlying  fundamental  prin- 
ciples of  Chemical  Warfare  are  the  same  as  for  all  other  arms. 
P)ecause  of  this,  it  is  worth  while,  and  even  necessary,  to  under- 
stand the  applications  of  Chemical  Warfare,  for  us  to  go  back 
and  study  the  work  of  the  masters  in  war  from  the  dawn  of 
history  down  to  the  present.  When  we  do  that  we  find  that 
the  underlying  fundamental  principles  of  war  remain  un- 
changed. They  are  the  same  to-day  as  they  were  in  the  time 
of  Demosthenes,  and  as  they  will  be  10,000  years  from  now. 
It  is  an  axiom  that  the  basis  of  success  in  war  is  ihp.  flbility  to 
have  at  the  decisive  point  at  the  decisive  mom^ut-a^  more 
effective  force  than  that  of  the  enemy.  This  involves  men 
and  materials.  It  involves  courage,  fight ing_ability^  and  the 
discrimination  and  energy  of  the  opposing  commanders. 

Another  fundamental  is  that  no  success  is  achieved  without 
positive  action ;  passive  rpsistflTipp  npy^^f  wins  These  are  really 
unchanging  fundamentals.  We  may  also  say  that  the  vigor  of 
attack,  the  speed  of  movement  of  men  and  supplies,  and  the 
thorough  training  of  men  in  the  use  of  the  weapons  of  war 
are  unchanging  requirements,  but  outside  of  these  everything 
is  subject  to  the  universal  law  of  change. 

Grecian  Phalanx  and  Roman  Legion.  The  last  word  in  the 
development  of  human  strength  as  a  battle  weapon  was  illus- 
trated by  the  Grecian  phalanx  with  its  sixteen  rows  of  men, 
the  spears  of  each  row  being  so  adjusted  that  all  reached  to 
the  front  line.    That  phalanx  could  not  be  stopped  by  any  other 

*  This  material  is  adapted  from  a  lecture  by  Gen.  Fried  before  the 
students  of  the  General  Staff  College,  in  Washington,  May  11,  1921. 

363 


364  CHEMICAL  WARFARE 

human  formation  that  met  it  face  to  face.  To  overcome  it 
required  a  Roman  legion  that  could  open  up  and  take  the 
phalanx  in  the  flank  and  rear.  In  the  same  way,  the  elephants 
of  the  Africans  and  the  chariots  of  the  Romans  with  their  great 
swords  swept  all  in  front  of  them,  until  the  Roman  Legion, 
opening  up  into  smaller  groups  allowed  the  elephants  and 
chariots  to  pass  through  only  to  close  in  on  them  from  the  rear. 
Then  and  then  only  did  those  engines  of  war  disappear  forever. 

Frederick  the  Great.  Frederick  the  Great,  realizing  that 
rapidity  of  fire  would  win  on  the  fields  of  battle  where  he 
fought,  trained  his  men  to  a  precision  of  movement  in  close 
order  probably  never  achieved  by  any  other  troops  in  the  world 
and  then  added  to  their  efficiency  by  teaching  them  to  load 
and  fire  muskets  at  double  the  rate  of  that  of  his  adver- 
saries. He  was  thus  enabled  to  concentrate  at  the  decisive 
points  a  preponderance  of  power,  which  swept  all  his  enemies 
before  him. 

Napoleon.  Napoleon  achieved  the  same  decisive  power  in 
a  different  way.  Realizing  that  his  French  troops  could  not 
stand  the  rigorous  training  that  the  Prussians  underwent,  he 
trained  them  to  fight  with  great  enthusiasm,  to  travel  long  dis- 
tances with  unheard-of  swiftness,  and  to  strike  the  enemy 
where  least  expected.  He  added  to  that  a  concentration  of 
artillery  until  then  not  thought  of  as  possible  on  the  field  of 
battle.  He,  of  course,  had  also  a  genius  for  organizing  and 
keeping  up  his  supply. 

Grant  and  Jackson.  Grant  at  Vicksburg  and  Stonewall 
Jackson  in  the  Shenandoah  Valley  and  at  Chancellorsville, 
achieved  the  same  results  in  different  ways.  In  every  case  the 
fundamental  principle  of  concentrating  the  greatest  force  at 
the  decisive  point  at  the  vital  moment  in  the  battle  remained 
the  same.  The  methods  for  achieving  that  end  change  with 
every  age,  and  every  commander  of  world-wide  renown  de- 
veloped something  new  or  used  an  old  method  in  a  new  way. 
And  that  is  the  fundamental  requirement  for  a  successful  gen- 
eral. Hannibal,  Hasdrubal,  Caesar,  Napoleon,  Frederick  the 
Great,  Scott,  Grant,  and  Jackson  were  all  independent  thinkers. 
Each  and  every  one  dared  to  do  something  that  every  other 
general  and  statesman  of  his  time  told  him  could  not  be  done 


RELATION  TO  STRATEGY  AND  TACTICS  365 

or  that  would  bring  about  disaster.  They  had  the  courage  of 
their  convictions.  They  had  the  courage  to  think  out  new 
ideas  and  to  develop  them,  and  then  they  had  the  courage  to 
carry  through  those  convictions,  not  alone  against  the  opposi- 
tion of  the  enemy,  but  against  the  opposition  of  their  own 
people,  both  in  the  field  and  at  home.  And  we  may  be  per- 
fectly sure  that  in  each  case  had  these  men  not  done  the  things 
they  did,  they  would  have  gone  down  to  oblivion  just  as  has 
been  the  case  with  millions  of  others  who  tried  the  usual 
methods  in  the  usual  way. 

Chemical  Warfare  Latest  Development.  Chemical  Warfare 
is  the  latest  development  of  war.  So  far  as  the  United  States 
is  concerned,  it  is  considerably  less  than  four  years  old.  It  is 
the  most  scientific  of  all  methods  of  fighting  and  also  the  most 
universally  applicable  to  all  other  methods  of  making  war.  Theli 
use  of  poisonous  and  irritating  gases  in  war  is  just  as  funda-  ! 
mental  as  the  introduction  of  gunpowder.     In  fact,  they  have 


'} 


an  even  wider  application  to  war  than  powder  itself. 

Necessity  for  New  Methods.     The  idea  that  has  been  eSlj 
pressed  above  is  that  the  General  Staff  and  the  Army  com-n 
mander  who  sticks  to  old  and  tried  methods  and  who  is  unwill- 
ing to  try  with  all  his  might  new  developments,  will  never  | 
achieve  any  first-class  success.     The  General  Staffs  and  thej 
generals  of  the  future  that  win  wars  will  be  the  ones  who 
make  the  most  vigorous  and  efficient  use  of  Chemical  Warfare 
materials.     They  cannot  confine  this  use  to  the  artillery,  to 
Aviation,  to  Special  Gas  Troops,  or  to  any  other  single  branch 
of  the  war  machine.    They  must  make  use  of  it  in  every  way. 

What  Is  Meant  by  Gas.  It  must  be  understood  that  by 
gases  we  refer  to  materials  that  injure  by  being  carried  to  the 
victim  in  the  air.  The  word  ''gas"  has  nothing  whatever  to 
do  with  the  condition  of  the  material  when  in  the  shell,  or  the 
bombs,  or  the  cylinders  before  released.  In  every  case,  the 
gases  are  liquids  or  solids.  When  the  containers  are  broken 
open  the  liquids  are  volatilized  either  by  the  gas  pressure  or  by 
the  force  of  the  explosion  of  the  bomb. 

Groups  of  Gases.  Chemical  Warfare  gases  are  divided  into 
three  great  gi^oups.  So  far  as  their  actual  tactical  use  on  the 
field  of  battle  is  concerned,  there  are  only  two  groups — per- 


366  CHEMICAL  WARFARE 

sistent  and  non-persistent.  The  third  is  the  irritant  group. 
This  group  affects  the  eyes  and  the  lungs  so  as  to  make  the 
victim  very  uncomfortable  if  not  completely  incapable  of  action 
in  quantities  so  small  as  to  cause  no  injury  that  lasts  more  than 
a  few  hours.  The  quantities  of  such  gases  needed  to  force  the 
wearing  of  the  mask  is  ^Aooo  that  needed  to  cause  the  same 
discomfort  by  the  really  poisonous  gases,  such  as  phosgene. 
They,  therefore,  have  a  very  great  economic  value  in  harassing 
the  enemy  by  forcing  him  to  wear  masks  and  to  take  other 
precautions  against  gas.  And  no  matter  how  perfect  gas  masks 
and  gas-proof  clothing  become,  their  long-continued  use  will 
cut  down  physical  vigor  in  an  ever-increasing  ratio  until  in 
two  or  three  days  an  army  may  be  totally  incapacitated. 

Smoke.  In  Chemical  Warfare  materials  we  have  another 
great  group  which  will  probably  be  equal  in  the  future  to  the 
three,  groups  just  mentioned.  That  is  common  smoke.  Smoke 
has  a  variety  of  uses.  By  the  simple  term  ''smoke"  is  meant 
smokes  that  are  not  poisonous  or  irritating.  Such  smokes  offer 
a  perfect  screen  against  enemy  vision,  whether  it  is  the  man, 
who  sights  the  machine  gun,  the  observer  in  the  lookout  sta- 
tion, the  cannoneer  or  even  the  aeroplane  observer.  Every  shot 
through  impenetrable  smoke  is  a  shot  in  the  dark  and  has  a 
tenth  or  even  less  chance  of  hitting  its  mark.  Smoke  affords 
a  means  of  decreasing  the  accuracy  of  firing,  much  the  same  as 
night  decreases  it,  without  the  inherent  difficulties  of  night 
action. 

Peace  Strategy.  The  strategy  of  successful  war  involves 
the  strategy  of  peace.  This  has  been  true  from  the  days  when 
David  with  his  sling-shot  slew  Goliath,  down  to  the  present 
moment.  We  don't  always  think  of  it  in  connection  with  war, 
but  back  of  every  successful  war  has  been  preparation  during 
peace.  It,  may  have  been  incidental  preparation  such  as  the 
training  of  men  in  fighting  Indians,  and  in  creating  public 
sentiment  favorable  to  an  independent  nation  that  preceded  the 
Revolutionary  War.  It  may,  on  the  other  hand,  have  been  a 
deeply  studied  policy  such  as  that  of  the  Germans  prior  to  the 
World  War.  They  tried  and  generally  quite  successfully,  to 
coordinate  all  peace  activities  toward  the  day  when  a  war 
should  come  that  would  decide  the  future  destiny  of  the  Ger- 


.  RELATION  TO  STRATEGY  AND  TACTICS  367 

man  Empire,  and  it  was  only  because  of  that  study  in  peace 
that  Germany  almost  single-handed  was  able  to  stand  out  for 
more  than  four  years  against  the  world.  The  Allies  came  near 
losing  that  war  because  they  did  not  appreciate  that  the 
strategy  of  efficient  war  had  to  be  preceded  by  the  strategy  of 
peace. 

Chemical  Warfare  an  Example.  Chemical  warfare  is  a  par- 
ticularly good  example  of  this  fact.  Prior  to  the  World  War 
WG  had  acknowledged,  and  without  any  misgivings,  that  Ger- 
many led  the  world  in  chemistry,  that  it  produced  most  of  the 
dyes  in  the  world,  and  to  a  large  extent  the  medicines  of  the 
world.  We  felt  that  when  American  needs  showed  it  to  be 
advisable  we  could  take  up  chemistry  and  chemical  production 
and  soon  excel  the  Germans.  We  had  not  reckoned  on  the  sud- 
denness of  war. 

We  were  just  getting  ready  with  chemicals,  and  that  in- 
cluded powders  and  high  explosives,  when  the  war  closed.  And 
yet  we  had  had  not  only  eighteen  months'  intensive  preparation 
after  our  own  entry  into  the  World  War,  but  also  the  prepara- 
tion of  great  steel  institutions  and  powder  factories  for  nearly 
three  years  in  manufacturing  supplies  for  the  Allies  who  pre- 
ceded us  in  the  war. 

Coal  Tar.  The  World  War  opened  the  eyes  of  England, 
France  and  Japan  as  well  as  the  United  States.  Each  of  them 
to-day  is  struggling  to  build  up  a  great  chemical  industry  as 
the  very  foundation  of  successful  war.  Few  of  us  realized 
prior  to  the  World  War  that  in  the  black,  sticky  mess  called 
coal  tar  from  the  coking  of  coal  or  the  manufacture  of  gas 
from  coal  and  oil,  was  stored  up  most  of  the  high  explosives 
used  in  war,  the  majority  of  the  poison  gases,  a  great  deal  of 
the  medicines  of  the  world,  and  nearly  all  the  dyes  of  the  world. 
Tha  Germans  realized  it  and  in  their  control  over  methods 
of  using  this  material,  together  with  the  great  commercial 
plants  developed  to  manufacture  it,  as  well  as  with  the  trained 
personnel  that  must  go  with  such  plants,  were  enabled,  when 
blockaded  on  land  and  sea,  to  furnish  the  munitions,  the  cloth- 
ing and  the  food  needed  for  four  and  one-half  years  of  war. 

Great  Chemical  Industries.  Thus  it  is  that  our  Government 
to-day  is  giving  most  serious  heed  to  the  need  of  building  up 


368  CHEMICAL  WARFARE 

a  great  chemical  industry  in  the  United  States.  We  have  the 
raw  materials.  We  need  only  the  factories  and  the  trained 
men  that  go  with  them.  We  need,  of  course,  in  addition  to 
the  development  of  the  coal  tar  industry,  a  production  of  heavy 
chemicals  such  as  chlorine,  sulfuric  acid  and  the  like,  all  of 
which,  however,  are  bound  together  by  community  interest  in 
peace  as  well  as  in  war. 

Reserves  of  Chemists.  A  part  of  the  strategy  of  peace  is 
the  card-indexing  of  the  manpower  of  a  nation  divided  into 
special  groups.  In  one  great  group  must  come  those  who  have 
a  knowledge  of  chemistry  and  the  chemical  industries.  That 
must  be  so  worked  out  that  if  war  should  come  on  a  moment's 
notice,  within  twenty-four  hours  thereafter  every  chemist  could 
be  given  his  job,  jobs  extending  from  the  firing  line  to  the  re- 
search laboratory.  And  that  is  the  task  of  the  Chemical  War- 
fare Service.  And  right  here  it  is  .well  to  know  that  Congress, 
among  the  other  features  of  its  Army  Reorganization  Act  of 
June  4,  1920,  provided  for  a  separate  Chemical  Warfare  Ser- 
viee^with^fehese-pirw^rsi  ^ 

Chemical  Warfare  Powers 

The  Chief  of  the  Chemical  Warfare  Service  under  the  authority  of 
the  Secretary  of  War  shall  be  charged  with  the  investigation,  develop- 
ment, manufacture,  or  procurement  and  supply  to  the  Army  of  all 
smoke  and  incendiary  materials,  all  toxic  gases,  and  all  gas-defense 
apphances;  the  research,  design,  and  experimentation  connected  with 
chemical  warfare  and  its  material ;  and  chemical  projectile  filling  plants 
and  proving-  grounds;  the  supervision  of  the  training  of  the  Army 
in  chemical  warfare,  both  offensive  and  defensive,  including  the  neces- 
sary schools  of  instruction;  the  organization,  equipment,  training,  and 
operation  of  special  gas  troops,  and  such  other  duties  as  the  President 
may  from  time  to  time  prescribe. 

Why  Power  Is  Needed.  These  rather  broad  powers  indi- 
cate that  Congress  realized  the  unity  of  effort  that  must  be 
made  from  the  research  laboratory  to  the  firing  line  if  America 
was  to  keep  pace  with  Germany  or  any  other  nation  in  chemical 
warfare.  Some  have  raised  the  question  as  to  whether  a 
service  should  be  both  supply  and  combat.     Perhaps  the  best 


RELATION  TO  STRATEGY  AND  TACTICS  369 

answer  to  that  question  is  that  so  organized  Chemical  Warfare 
was  a  success  in  the  World  War.  It  was  a  success  notwith- 
standing- it  had  to  be  developed  in  the  field  six  months  after 
our  entry  into  the  war  and  with  no  precedents,  no  materials, 
no  literature  and  no  personnel.  Through  its  officers  on  the 
staffs  of  commanding  generals  of  armies,  corps  and  divisions, 
and  through  its  fighting  gas  troops  in  the  front  line,  it  was 
enabled  to  direct  its  research,  development  and  manufacture 
more  quickly  along  lines  shown  to  be  necessary  by  every  change 
in  battle  conditions,  than  any  other  service. 

Chemical  Warfare  Troops.  And  why  should  there  not  be 
fighting  Chemical  Warfare  troops?  They  fight  under  exactly 
the  same  orders  as  all  other  troops.  They  conform  to  the  same 
general  plan  of  battle.  They  bring,  however,  to  that  battle 
experts  in  a  line  that  it  takes  a  long  time  to  master.  And  where 
has  there  been  any  live  commander  in  the  world's  history  who 
refused  aid  from  any  class  of  troops  that  might  help  him  win? 

Specialists  in  War.  The  wars  of  the  future  will  become 
more  and  more  wars  of  the  specialists.  Your  Infantry  may 
remain  the  backbone  of  the  fighting  force,  but  if  it  has  not  the 
Artillery,  the  AA^iation,  the  Chemical  Warfare,  the  Engineers, 
the  tanks  and  other  specialists  to  back  it  up,  it  will  be  over- 
come by  the  army  which  has  such  specialists.  Indeed  the 
specialist  goes  into  the  very  organization  of  the  Infantry  itself 
with  its  machine  gun  battalions,  its  tank  battalions,  and  as  now 
proposed,  the  Infantry  light  howitzer  companies. 

Duties  of  Chemical  Warfare  Staff  Officers.  The  Chemical 
Warfare  officers  on  the  staff  of  armies,  corps  and  divisions  are 
there  for  the  purpose  of  giving  expert  advice  as  to  the  quan- 
tities of  chemical  materials  available,  the  best  conditions  for 
using  them,  and  the  best  way  of  avoiding  the  effects  of  enemy 
gas  upon  our  own  troops.  The  conditions  that  must  be  kept  in 
mind  are  so  many  that  no  other  officer  can  be  expected  to  master 
and  keep  them  if  he  does  his  own  work  well.  The  general 
staff  officers  and  commanding  generals  will  not  have  the  time 
to  even  try  to  remember  the  actual  effects  of  clouds,  wind,  rain, 
trees,  valleys,  villages  and  plains  upon  each  and  every  gas. 
They  must  depend  upon  the  Chemical  Warfare  officer  for  accu- 
rate information  along  those  lines,  and  if  he  cannot  furnish  it 


370  CHEMICAL  WARFARE 

they  will  have  to  secure  some  one  who  can.  The  history  of 
war  is  filled  with  the  names  of  generals  who  failed  because 
they  conld  not  forget  how  to  command  a  company.  These 
Chemical  Warfare  officers  will  also  furnish  all  data  as  to  supply 
of  chemical  warfare  materials,  and  will  furnish  the  best  infor- 
mation along  lines  of  training,  whether  for  defensive  or  offen- 
sive use  of  gas. 

Gras  Used  by  all  Arms.  As  before  stated,  we  cannot  confine 
the  use  of  gas  to  any  one  arm.  We  may  then  ask  why,  if  it 
is  applicable  to  all  arms,  it  should  need  special  gas  troops. 
Special  gas  troops  are  for  the  purpose  of  putting  off  great 
quantities  of  chemical  warfare  materials  by  special  methods 
that  are  not  applicable  to  any  other  branch  now  organized 
or  that  any  other  branch  has  the  time  to  master.  Long-range 
firing  of  gas  by  the  artillery  can  be  done  just  as  well  by  the 
artillery  as  by  gas  troops.  Why?  Because  in  the  mechanics 
of  firing  chemical  ammunition  there  is  no  difference  whatever 
from  the  mechanics  of  firing  high  explosives  or  shrapnel.  The 
same  will  be  true  of  gas  rifle  grenades  and  smoke  candles  in 
use  by  the  Infantry.  The  same  will  be  true  of  the  dropping 
of  gas  bombs  and  the  sprinkling  of  gas  by  the  aeroplanes.  In 
this  connection  just  remember  that  all  of  the  army  is  trained 
in  first  aid,  but  in  addition  we  have  our  ambulance  companies, 
our  hospitals,  and  our  trained  medical  personnel. 

Arguments  Against  Use  of  G-as.  It  has  been  many  times 
suggested  since  the  Armistice  that  the  use  of  poisonous  gas  in 
Vv^ar  may  be  done  away  with  by  agreement  among  nations. 
TJie  arguments  against  the  use  of  gas  are  that  itjs_inhiiinane 
and  that  it  might  b-e_  used  against  non-CQmbatant,Sj__especially 
women  and  diildren.  The  inhumanity  of  it  is  absg]ut_ely  dis- 
proven  by  the  results  of  its  use  in  the  AVorld  War.  The  death 
rate  from  gas  alone  was  less  than  one-twelfth  that  from  bullets, 
high  explosives  and  other  methods  of  warfare.  The  disability 
rate  for  gas  patients  discharged  was  only  about  one-fourth 
that  for  the  wounded  discharged  for  other  causes.  The  per- 
manently injured  is  likewise  apparently  very  much  less  than 
from  other  causes. 
«^  Humanity.  No  reliable  statistics  that  we  cf  n  get  show  that 
gas  in  any  way  causes  tuberculosis  any  more  than  a  severe 


RELATION  TO  STRATEGY  AND  TACTICS  371 

attack  of  bronchitis  or  pneumonia  causes  tuberculosis.  Since 
its  principal  effects  are  upon  the  lungs  and,  therefore,  hidden 
from  sight,  every  impostor  is  beginning  to  claim  gassing  as  the 
I'cason  for  his  wanting  War  Risk  benefits  from  the  Govern- 
ment. We  do  not  claim  there  may  not  be  some  who  are  suf- 
fering permanent  injuries  from  gas,  and  we  are  trying  very 
liard  to  find  out  from  the  manufacturers  of  poisonous  gases 
and  allied  chemicals  if  they  have  any  authentic  records  of  such 
cases.  So  far  the  results  indicate  that  permanent  after-effects 
are  very  rare. 

As  to  non-combatants,  certainly  we  do  not  contemplate 
using  poisonous  gas  against  them,  nQ_more  at  least  than  we 
propose  to  use  high  explosives  in  long  range  guns  or  aeroplanes 
against  them.  The  use  of  the  one  against  non-combatants  is 
just  as  damnable  as  the  other  and  it  is  just  as  easy^.to  refrain 
fi'ora._ using  one  as  the  other. 

Gas  Cannot  be  Abolished.  As  to  the  abandonment  of  poison  9^ 
gas,  it  must  be  remembered  that  no  powerful  weapon  of  war 
lias  ever  been  abandoned  once  it  proved  its  power  unless  a 
more  powerful  weapon  was  discovered.  Poisonous  gas  in  the 
World  War  proved  to  be  one  of  the  most  powerful  of  all 
weapons  of  war.  For  that  reason  alone  it  will  never  be  aban- 
doned. It  cannot  be  stopped  by  agreement,  because  if  you 
can  stop  the  use  of  any  one  powerful  weapon  of  war  by  agree- 
ment you  can  stop  all  war  by  agreement.  To  prepare  to  use 
it  only  in  case  it  is  used  against  you  is  on  the  same  plane  as 
an  order  that  was  once  upon  a  time  issued  to  troops  in  the 
Philippine  Islands.  That  order  stated  in  substance  that  no 
officer  or  soldier  should  shoot  a  savage  Moro,  even  were  he 
approaching  the  said  officer  or  soldier  with  drawn  kriss 
(sword),  unless  actually  first  struck  by  such  savage.  Every 
officer  preferred,  if  necessary,  to  face  a  court-martial  for  dis- 
obedience of  such  an  order  rather  than  allow  a  savage  Moro 
with  a  drawn  kriss  to  get  anywhere  near,  let  alone  wait  until 
a^'tually  struck. 

Let  the  world  know  that  we  propose  to  use  gas  against 
alljtroops  that  may  be  engaged  against_us^  and  that  we  pro- 
l)ose  to  use  it  to  the  fullest  extent  oijiur_aMlity.  We  believe 
that  such  a  proposition  will  do  more  to  head  off  vjrar  than  all 


372  CHEMICAL  WARFARE 

the  peace  propaganda  since  time  began.  It  has  been  said  that 
we  should  not  use  gas  against  those  not  equipped  with  gas. 
Then  why  did  we-  use  repeating  rifles  and  machine  guns  against 
Negritos  and  Moros  armed  only  with  bows  and  arrows  or  poor 
1  muskets  and  knives.  Let  us  apply  the  same  common  sense  to 
^  the  use  of  gas  that  we  apply  to  all  other  weapons  of  waf.J 

Effect  on  World  War  Tactics.  A  very  brief  study  of  the 
effects  of  chemical  warfare  materials  on  the  strategy  of  the 
World  War  will  indicate  its  future.  It  began  with  clouds  of 
chlorine  let  loose  from  heavy  cylinders  buried  under  the  firing 
trench.  These  took  a  long  time  to  install  and  then  a  wait, 
sometimes  long,  sometimes  brief,  for  a  favorable  wind,  but  even 
at  that  these  cloud  gas  attacks  created  a  new  method  of  fight- 
ing and  forced  new  methods  of  protection.  Gas  at  once  added 
a  tremendous  burden  to  supply  in  the  field,  to  manufacture, 
and  to  transportation,  and  in  a  short  time  even  made  some  de- 
cided changes  in  the  tactics  of  the  battle  field  itself. 

Cloud  Gas.  The  fact  that  the  gas  cloud  looked  like  smoke 
is  responsible  for  the  name  ' '  cloud  gas. ' '  Really  all  gases  are 
nearly  or  wholly  invisible,  but  those  which  volatilize  suddenly 
from  the  liquid  state  so  cool  the  air  as  to  cause  clouds  of  con- 
densed water  vapor.  The  cloud  obscured  everything  behind 
and  in  front  of  it.  It  led  the  German  to  put  off  fake  smoke 
clouds  and  attack  through  them,  thus  taking  the  British  at  a 
tremendous  disadvantage.  Then  and  there  began  a  realization 
of  the  value  of  smoke.  Cloud  gas  was  also  the  real  cause  of 
the  highly  organized  raid  that  became  common  in  every  army 
during  the  World  War.  The  real  purpose  in  the  first  raids, 
carried  out  by  means  of  the  box  barrage,  was  to  find  out 
whether  or  not  gas  cylinders  were  being  installed  in  trenches. 

These  raids  finally  became  responsible,  in  a  large  measure, 
for  driving  the  old  cloud  gas  off  the  field  of  battle.  It  did  not, 
however,  stop  the  British  from  putting  off  cloud  gas  attacks  in 
1918  by  installing  their  gas  cylinders  on  their  light  railway 
cars  and  then  letting  the  gas  loose  from  the  cylinders  while 
still  on  the  cars.  This  enabled  them  to  move  their  materials 
to  the  front  and  put  off  gas  attacks  on  a  few  hours'  notice 
when  the  wind  was  right. 

Toxic  Smoke  Candles.    To-day  we  have  poisonous  smokes 


RELATION  TO  STRATEGY  AND  TACTICS  373 

that  exist  in  solid  form  and  that  are  perfectly  safe  to  handle 
until  a  fuse  is  lighted.  The  so-called  candles  will  be  light 
enough  so  that  one  man  can  carry  them.  With  these,  cloud 
gas  can  be  put  off  on  an  hour 's  notice  when  wind  and  weather 
conditions  are  right,  no  matter  how  fast  the  army  may  be 
moving  and  whether  on  the  advance  or  in  retreat.  Cloud  gas 
will  usually  be  put  off  at  night  because  the  cloud  cannot  be 
seen,  because  then  men  are  tired  and  sleepy,  and  all  but  the 
most  highly  trained  become  panicky.  Under  those  conditions 
the  greatest  casualties  result.  The  steadiness  of  wind  currents 
also  aids  cloud  gas  attacks  at  night. 

Value  of  Training  in  Peace.  And  this  brings  up  the  value 
of  training  in  peace.  We  are  frequently  asked,  *'Why  do  you 
need  training  with  masks  in  peace ;  why  do  you  need  training 
with  actual  gas  in  peace ;  cannot  these  things  be  taught  on  short 
notice  in  war  ? ' '  The  answer  is,  "  No !  * '  Nothing  will  take  the 
place  of  training  in  peace. 

All  of  us  recall  that  early  in  the  war  the  Germans  spread 
broadcast  charges  that  the  Allies  were  using  unfair  and  inhu- 
mane methods  of  fighting  because  they  brought  the  Ghurka 
with  his  terrible  knife  from  Asia  and  the  Moroccan  from  Africa. 
And  we  all  know  that  after  a  time  the  Germans  ceased  saying 
anything  about  these  troops.  What  was  the  cause  ?  They  were 
not  efficient.  Just  as  the  Negro  will  follow  a  white  officer  over 
tlie  top  in  daylight  and  fight  with  as  much  energy  and  courage 
and  many  times  as  much  efficiency  as  the  white  man,  he  cannot 
stand  the  terrors  of  the  night,  and  the  same  was  true  of  the 
Ghurka  and  the  Moroccan. 

All  the  Allies  soon  recognized  that  fact  as  shown  by  their 
drawing  those  troops  almost  entirely  away  from  the  fighting 
lines.  In  some  cases  dark-skinned  troops  were  kept  only  as 
shock  troops  to  be  replaced  by  the  more  highly  developed  Cau- 
casian when  the  line  had  to  be  held  for  days  under  the  deadly 
fire  of  the  counter  attack.  The  German  idea,  and  our  own 
idea  prior  to  the  World  War,  was  that  semi-savages  could 
stand  the  rigors  and  terrors  of  war  better  than  the  highly  sen- 
sitive white  man.    War  proved  that  to  be  utterly  false. 

Familiarity  with  Gas  Necessary.  The  same  training  that 
makes  for  advancement  in  science,  and  success  in  manufacture 


374  CHEMICAL  WARFARE 

in  peace,  gives  the  control  of  the  body  that  holds  the  white 
man  to  the  firing  line  no  matter  what  its  terrors.  A  great  deal 
of  this  comes  because  the  white  man  has  had  trained  out  of 
him  nearly  all  superstition.  He  has  had  drilled  into  him  for 
hundreds  of  years  that  powder  and  high  explosive  can  do  cer- 
tain things  and  no  more.  If  the  soldier  is  not  to  be  afraid  of 
gas  we  must  give  him  an  equal  knowledge  of  it,  its  dangers, 
and  its  limitations.  The  old  adage  says,  ''Familiarity  breeds 
contempt."  Perhaps  that  is  not  quite  true,  but  we  all  know 
that  it  breeds  callousness  and  f orgetfulness ;  that  the  man  man- 
ufacturing dynamite  or  other  more  dangerous  explosives  takes 
chances  that  we  who  do  not  engage  in  such  manufacture 
shudder  at. 
A-  Ed^ewood  Chemists  Not  Afraid.  All  of  this  has  direct 
application  to  training  with  chemical  warfare  materials  in 
peace.  We  helieve  that  all  opposition  to  chemical  warfare  to-day 
can  he  divided  into  two  classes — those  who  do  not  understand 
it  and  those  who  are  afraid  of  it — ignorance  and  cowardice. 
Our  chemists  at  Edgewood  Arsenal  are  every  day  toying  with 
the  most  powerful  chemical  compounds;  toying  with  mixtures 
they  know  nothing  of,  not  knowing  what  instant  they  may 
induce  an  explosion  of  some  fearful  poisonous  gas.  But  they 
have  learned  how  to  protect  themselves.  They  have  learned 
that  if  they  stop  breathing  and  get  out  of  that  place  and  on 
the  windward  side  they  are  safe.  They  have  been  at  that  work 
long  enough  to  do  that  automatically. 
^  Staff  Officers  Must  Think  of  Gas  in  Every  Problem.  The 
staff  officer  must  train  the  army  man  in  peace  with  all  chemical 
^\\U^^  warfare  materials  or  he  will  lose  his  head  in  war  and  become 
ffiP^  a  casualty.  The  general  staff  officers  aild  commanding  generals 
jA  must  so  familiarize  themselves  with  these  gases  and  their  gen- 
eral use  that  they  will  think  them  in  all  their  problems  just 
exactly  as  they  think  of  the  Infantry,  or  of  the  Cavalry,  or 
of  the  tanks  or  of  the  Artillery  in  every  problem.  On  them 
rests  the  responsibility  that  these  gases  are  used  properly  in 
battle.  If  plans  before  the  battle  do  not  include  these  materials 
for  every  arm  and  in  the  proper  quantities  of  the  proper  kinds 
they  will  not  be  used  properly  on  the  field  of  battle  and  on 
them  will  rest  the  responsibility. 


RELATION  TO  STRATEGY  AND  TACTICS  375 

They  are  not  expected  to  know  all  the  details  of  gases  and 
their  uses,  but  they  will  be  expected  to  consider  the  use  of  gas 
in  every  phase  of  preparing  plans  and  orders  and  then  to 
appeal  to  the  chemical  warfare  officers  for  the  details  that 
will  enable  them  to  use  the  proper  gases  and  the  proper  quan- 
tities. They  cannot  go  into  those  details  any  more  than  they 
can  go  into  tlie  details  of  each  company  of  infantry.  If  they 
try  to  do  that  tliey  are  a  failure  as  staff  officers. 

Effect  of  Masks  on  Troops.  The  very  best  of  masks  cause  ^ 
a  little  decrease  in  vision,  a  little  increase  in  breathing  resist- 
ance, and  a  little  added  discomfort  in  warm  weather,  and  hence 
the  soldier  must  learn  to  use  them  under  all  conditions.  But 
above  all  in  the  future  he  must  be  so  accustomed  to  the  use 
of  the  mask  that  he  will  put  it  on  automatically — almost  in 
his  sleep  as  it  were.  We  have  tear  gases,  to-day,  so  powerful 
and  so  sudden  in  their  action  that  it  is  doubtful  if  one  man 
out  of  five  who  has  had  only  a  little  training  can  get  his  mask 
on  if  subject  to  the  tear  gas  alone — that  is,  with  tear  gas 
striking  him  with  full  force  before  he  is  aware  of  it. 

Effectiveness  of  Gas  in  World  War.  In  the  past  war  more 
than  27  out  of  every  100  Americans  killed  and  wounded  suf- 
fered from  gas  alone.  You  may  say  that  many  of  the  wounds 
were  light.  That  is  true ;  but  those  men  were  put  out  of  the 
battle  line  for  from  one  to  four  months — divisions,  corps  and 
armies  almost  broken  up — and  yet  the  use  of  gas  in  that  war 
was  a  child's  game  compared  to  what  it  will  be  in  the  future. 

It  is  even  said  that  many  of  them  were  malingerers.  Per- 
haps they  were,  but  do  you  not  suppose  that  there  were  at  least 
as  many  malingerers  among  tjie  enemy  as  there  were  in  our 
own  ranks?  Furthermore,  if  you  can  induce  malingering  it 
is  a  proper  method  of  waging  war,  and  unless  our  tToasted 
ability  is  all  a  myth  we  should  have  fewer  malingerers  under 
conditions  of  battle  than  any  other  nation. 

Strategy  of  Gas  at  Picardy  Plains.  Let  us  go  back  nowHo 
the  strategy  of  gas  in  war.  Following  the  cloud  gas  came  tear 
gases  and  poisonous  gases  in  shells  and  bombs.  A  little  advance 
in  tactics  here  and  a  little  there,  the  idea,  though,  in  the  early 
days  being  only  to  produce  casualties.  As  usual  the  Germans 
awoke  first  to  the  fact  that  gas  might  be  used  strategically  and 


376  CHEMICAL  WARFARE 

on  a  large  scale.  And  thus  we  find  that  ten  days  before  he  began 
the  battle  of  Picardy  Plains  he  deluged  many. sections  of  the 
front  with  mustard  gas.  He  secured  casualties  by  the  thousands, 
but  he  secured  something  of  greater  importance.  He  wore  out 
the  physical  vigor  and  lowered  the  morale  of  division  after 
division,  thus  paving  the  way  for  the  break  in  the  British 
Army  which  almost  let  him  through  to  the  sea. 

He  used  non-persistent  gases  up  to  the  very  moment  when 
his  own  men  reached  the  British  lines,  thereby  reducing  the 
efficiency  of  British  rifle  and  artillery  fire  and  saving  his  own 
^men.  And  this  is  just  a  guide  to  the  future.  A  recent  writer 
in  the  Field  Artillery  Journal  states  that  gas  will  probably  not 
be  used  in  the  barrage  because  of  its  probable  interference  with 
the  movement  of  our  own  troops.  In  making  that  statement 
he  forgot  the  enemy  and  you  cannot  do  that  if  you  expect  to 
win  a  war. 

Gas  in  Barrages.  In  the  future  we  must  expect  the  enemy 
to  be  in  a  measure  as  well  prepared  in  chemical  warfare  as  we 
are.  Let  us  consider  the  special  case  of  our  own  men  advanc- 
ing to  the  attack  behind  a  rolling  barrage.  "We  will  consider 
also  that  the  wind  is  blowing  toward  our  own  troops.  Obviously 
under  those  conditions  the  wind  will  blow  our  own  gas  back 
onto  our  troops.  Will  we  use  gas  in  that  barrage?  We  cer- 
tainly will !  Because  with  the  wind  blowing  toward  our  own 
troops  we  have  the  exact  ideal  condition  that  the  enemy  wants 
for  his  use  of  gas.  He  will  then  be  deluging  our  advancing 
troops  with  all  the  gas  he  can  fire,  in  addition  to  high  explo- 
sives and  shrapnel.  Our  men  must  wear  masks  and  take  every 
precaution  against  enemy  gas.  How  foolish  it  would  be  not  to 
fire  gas  at  the  enemy  under  those  conditions.  If  we  did  not 
fire  gas  we  would  leave  him  entirely  free  from  wearing  masks, 
and  entirely  free  from  taking  every  other  precaution  against 
gas  while  our  own  troops  were  subject  to  all  the  difficulties  of 
gas.  No,  we  will  fire  gas  at  him  in  just  as  great  quantities 
as  we  consider  efficient.  And  that  is  just  a  sample  of  what  is 
coming  on  every  field  of  battle — gas  used  on  both  sides  by 
every  method  of  putting  it  over  that  can  be  devised. 

World  War  Lessons  Only  Guide  Posts.  Example  of  Book 
Worms.     Every  lesson  taught  by  the  World  War  must  be 


RELATION  TO  STRATEGY  AND  TACTICS  377 

taken  as  a  guide-post  on  the  road  to  future  success  in  war. 
No  use  of  gas  or  other  materials  in  the  past  war  must  be  taken 
as  an  exact  pattern  for  use  in  any  battle  of  the  future.  Too 
much  study,  too  much  attention  to  the  past,  may  cause  that 
very  thing  to  happen.  A  certain  general  commanding  a  bri- 
gade in  the  Argonne  told  me  just  recently  that  while  the  battle 
was  going  on  a  general  staff  officer  called  him  on  the  telephone 
and  asked  him  what  the  situation  was.  He  gave  it  to  him. 
The  staff  officer  then  asked,  ''What  are  you  doing?"  and  he 
told  him.  The  staff  officer  replied,  ''Why,  the  book  doesn't 
say  to  do  it  that  way  under  such  conditions. ' '  There  you  have 
the  absurd  side  of  too  much  study  and  too  close  reliance  on 
details  of  the  past. 

The  battle  field  is  a  perfect  kaleidoscope.  The  best  we  can 
hope  to  get  out  of  books  is  a  guide — something  that  we  will 
keep  in  our  minds  to  help  us  decide  the  best  way  to  meet  cer- 
tain situations.  He  who  tries  to  remember  a  particular  position 
taught  in  his  school  with  the  idea  of  applying  that  to  actual 
use  in  battle  is  laying  the  foundation  for  absolute  failure.  Your 
expert  rifleman  never  thinks  back  when  he  goes  to  fire  a  shot 
as  to  just  what  his  instructor  told  him  or  what  the  book  said. 
He  just  concentrates  his  mind  on  the  object  to  be  attained, 
using  so  far  as  comes  to  him  facts  he  has  learned  from 
books  or  teachers.  Your  general  and  your  staff  must  do  the 
same. 

Infantry  Use  of  Gas.  A  few  words  about  how  we  will  use 
gas  in  the  future.  We  will  start  with  the  Infantry:  The 
Infantry  as  such  will  use  gas  in  only  two  or  three  ways.  They 
will  use  some  gas  in  rifle  grenades,  and  a  great  deal  more  smoke. 
We  speak  of  the  rifle  grenade  because  in  our  opinion  the  hand 
grenade  is  a  thing  of  the  past.  We  do  not  believe  there  will 
ever  be  used  in  the  future  any  grenade  that  is  not  applicable 
to  the  rifle.  The  Infantry  will  probably  often  carry  large  quan- 
tities of  gas  in  the  shape  of  the  toxic  smoke  candle.  These 
materials  being  solids  may  be  shot  up  by  rifles  or  artillery  fire, 
run  over  by  trucks  or  tractors,  or  trampled  and  still  be  harm- 
less. It  is  only  when  the  fuses  are  lighted  and  the  material 
driven  off  by  heat  that  they  are  dangerous.  In  using  these 
candles  under  these  conditions  you  must  have  sufficient  chem- 


378  CHEMICAL  WARFARE 

ical  warfare  officers  and  soldiers  to  get  the  necessary  control 
indicated  by  the  sun,  wind,  woods,  fogs,  ravines  and  the  like. 

Cavalry  Use  of  Gas.  Next  consider  the  Cavalry.  The  Cav- 
alry will  use  gas  practically  the  same  as  the  Infantry.  The 
chemical  warfare  troops  will  accompany  the  Cavalry  with 
Stokes '  mortars  or  other  materials  to  fire  gases  into  small  enemy 
strongholds  that  may  be  encountered  whether  machine  gun 
nests,  mountain  tops,  woods  or  villages.  They  will  do  this 
either  against  savages  or  civilized  people.  Methods  of  making 
these  materials  mobile  for  that  purpose  are  already  well  under 
way.  If  against  savages  and  one  does  not  want  to  kill  them, 
use  tear  gases — ^no  better  method  of  searching  out  hidden 
snipers  in  mountain  tops,  among  rocks,  or  villages,  in  ravines, 
or  in  forests  was  ever  invented. 

Use  of  Gas  by  Tanks.  The  tanks  will  employ  gas  in  the 
same  way  as  the  Infantry  with  the  possibility,  however,  that 
they  may  be  used  to  carry  large  quantities  of  gas  on  cater- 
pillar tractors  where  otherwise  it  would  be  difficult  to  move 
the  gas.  This  is  not  a  certainty,  but  is  a  situation  promising 
enough  to  warrant  further  study. 

Artillery  Use  of  Gas.  Your  Artillery  will  fire  gas  and 
smoke  in  every  caliber  of  gun.  There  is  a  tendency  now  to 
limit  gas  to  certain  guns  and  howitzers  and  to  limit  smoke  to 
even  a  smaller  number  of  guns.  This  is  a  mistake  that  we  are 
going  to  recognize.  A  very  careful  study  of  the  records  of 
the  war  show  that  more  casualties  were  produced  several  times 
over  by  a  thousand  gas  shells  than  by  a  thousand  high  explo- 
sive or  shrapnel.  And  that  is  because  gas  has  an  inherent  per- 
manence that  no  other  weapon  of  war  has. 

Permanency  of  Gas.  The  bullet  whistles  through  the  air 
and  does  its  work  or  misses.  The  high  explosive  shell  bursts, 
hurling  its  fragments  that  in  a  few  seconds  settle  to  earth, 
and  its  work  is  done.  The  shrapnel  acts  in  the  same  way,  but 
when  one  turns  loose  a  shell  of  gas  it  will  kill  and  injure  the 
same  as  the  high  explosive  shell  and  in  the  same  length  of  time 
and  in  addition  for  some  minutes  thereafter.  Even  with  the 
non-persistent  gases,  it  will  continue  on  its  way,  causing  death 
or  injury  to  every  unprotected  animal,  man  or  beast  in  its 


RELATION  TO  STRATEGY  AND  TACTICS  379 

path.  With  the  persistent  gases,  the  materials  from  each  shell 
may  persist  for  days. 

Variety  of  Uses  of  Gas.  This  brings  up  the  point  of  the 
great  variety  of  uses  to  which  gas  can  be  put.  The  non-per- 
sistent gas  may  be  used  at  all  times  where  one  wants  to  get 
rid  of  it  in  a  few  moments — the  persistent  gas  wherever  one 
wants  to  keep  the  enemy  under  gas  for  days  at  a  time.  We 
will  use  mustard  gas  on  strong  points  in  the  advance,  on 
flanks,  on  distant  areas  one  will  not  expect  to  be  reached, 
and  as  our  own  protection  of  masks  and  clothing  increases 
toward  perfection  we  will  use  it  on  the  very  fields  you  expect 
to  cross.  Why?  Because  we  will  be  firing  it  at  the  enemy  for 
days  before  hand  and  we  will  cause  him  trouble  all  those  days 
v/hile  we  ourselves  will  encounter  it  for  a  few  hours  at  the 
most.  So  do  not  think  that  mustard  gas  is  only  going  to  be 
used  in  defense  in  the  future. 

Solid  Mustard  Gas  and  Long  Range  Guns.  We  will  come 
to  use  chemical  warfare  materials  just  as  high  explosives  and 
bullets  are  used  to-day,  even  though  at  times  we  do  suffer  an 
occasional  loss  from  our  own  weapons.  Our  Artillery  in  long 
range  guns  where  we  want  destruction  will  fill  each  shell  with 
say  15  per  cent  gas  and  85  per  cent  high  explosive.  We  have 
a  solid  mustard  gas  that  may  be  so  used.  We  have  tremen- 
dously powerful  tear  gases  and  irritating  gases  that  may  be  so 
used.  Being  solids  they  do  not  affect  the  ballastic  qualities 
of  the  shell.  And  what  an  added  danger  will  mustard  gas  from 
every  shell  bring  against  railroad  centers,  rest  villages,  can- 
tonments, cross  roads  and  the  like.  The  results  will  be  too 
great  for  any  force  to  overlook  such  use. 

Tear  Gases  in  Shrapnel.  We  will  probably  use  tear  gas  in 
most,  if  not  all,  of  our  shrapnel.  The  general  idea  now  is  that 
we  should  not  put  tear  gas  in  all  shrapnel  because  under  certain 
conditions  it  will  be  blown  back  and  harass  our  own  troops. 
But  as  was  said  before,  we  must  remember  that  the  enemy 
will  be  using  gas  at  all  times  as  well  as  ourselves,  and  hence 
if  we  limit  ourselves  in  any  line  we  give  the  enemy  an  advan- 
tage. This  use  of  gas  by  the  Artillery  will  extend  to  all  classes 
of  guns — seacoast,  field,  turret  and  what  not. 


380  CHEMICAL  WARFARE 

Use  of  Gas  by  Air  Service.  Bombs.  Let  us  next  consider 
the  Air  Service.  We  naturally  think  of  dropping  gas  in  bombs 
v/hen  we  speak  of  the  use  of  gas  by  the  Air  Service.  Gas 
will  so  be  used  and  it  will  be  used  in  bombs  of  perhaps  a 
thousand  pounds  or  even  a  ton  in  weight,  at  least  50  per 
cent  of  which  will  be  gas.  Such  gases,  however,  will  be  of 
the  non-persistent  type — phosgene  or  similar  ones.  They 
will  be  used  against  concentration  camps  and  cross-roads, 
on  troops  on  the  road  in  columns;  against  railroad  centers 
and  rest  areas;  in  other  words,  against  groups  of  men  or 
animals. 

Sprinkling.  But  that  is  not  even  the  beginning  of  the  use 
of  gas  by  aeroplanes.  Mustard  gas,  which  is  one-third  again 
as  heavy  as  water,  and  which  volatilizes  far  slower  than  water, 
may  be  sprinkled  through  a  small  opening  such  as  a  bung  hole 
in  a  tank  that  simply  lets  liquid  float  out.  The  speed  of  the 
aeroplane  will  atomize  it.  In  this  way,  gas  can  be  sprinkled 
over  whole  areas  that  must  be  crossed  in  battle.  The  Lewisite, 
of  which  we  have  heard  considerable,  will  be  used.  It  is  less 
persistent  than  the  mustard  gas,  but  like  mustard  gas  it  pro- 
duces casualties  by  burning.  Unlike  mustard  gas,  however, 
the  burns  from  a  quantity  equal  to  three  drops  will  usually 
cause  death.  The  material  can  be  made  up  by  hundreds,  even 
thousands,  of  tons  per  month. 

We  are  working  on  clothing  that  will  keep  it  out  just  as 
we  have  been  and  are  working  on  clothing  that  will  protect 
against  mustard  gas.  But  these  gases  are  so  powerful  that  if 
any  opening  be  left  in  the  clothing  the  gas  will  get  through, 
so  that  even  if  we  get  clothing  that  will  protect,  it  must  cover 
every  inch  of  the  skin  from  head  to  foot.  Besides  the  mask 
must  be  worn  at  all  times. 

Consider  the  burden  put  on  any  army  in  the  field  that  would 
liave  to  continually  wear  such  complete  protection.  What  a 
strain  on  the  mentality  of  the  men !  As  before  said,  to  endure 
it  at  all  we  must  train  our  men  to  think  of  such  conditions,  to 
face  them  in  peace,  and  in  order  to  do  so  we  must  actually 
use  gas.  Just  as  in  the  World  War  the  highly  trained  Cau- 
casian outdistanced  the  savage  in  endurance,  just  so  will  the 


RELATION  TO  STRATEGY  AND  TACTICS  381 

most  highly  trained  men  in  the  future  outdistance  all  others 
in  endurance. 

Navy.  We  now  come  to  the  consideration  of  the  Navy. 
The  Navy  will  use  gas  both  in  its  guns  and  in  smoke  clouds, 
and  in  some  form  of  candle  that  will  float.  The  toxic  smokes 
that  in  high  enough  concentrations  will  kill  are  extraordinarily 
irritating  in  minute  quantities — so  minute  they  cannot  be  seen 
or  felt  for  a  few  moments.  Every  human  being  on  a  ship  must 
breathe  every  minute  just  as  every  human  being  everywhere 
must  breathe  every  minute  or  die.  A  gas  that  gets  into  the 
ventilating  system  of  a  ship  will  go  all  through  it  and  the  Navy 
realizes  it. 

The  Navy  is  studying  how  to  keep  the  gas  out  of  their  own 
ships,  and  how  to  get  it  into  the  enemy's  ships.  The  toxic 
smokes  may  be  dropped  from  aeroplanes  or  turned  loose  from 
under  water  by  submarines.  In  either  case  they  will  give  off 
smokes  over  wide  areas  through  which  ships  must  pass.  Any 
defects  will  let  these  toxic  smokes  in  and  will  force  every  man 
to  wear  a  mask.  Aeroplane  bombs  will  come  raining  down  on 
the  ship  or  alongside  of  it  either  with  toxic  smokes  or  other 
terrible  gases.  White  phosphorus  that  burns  and  cannot  be 
put  out  wet  or  dry  will  be  rained  on  ships.  Yes,  chemical  war- 
fare materials  will  be  used  by  the  Navy. 

Gas  Against  Landing  Parties.  The  use  of  gas  against  land- 
ing parties  or  to  aid  landing  parties  has  come  up  in  many 
Vv^ays.  Our  studies  to  date  indicate  that  gas  is  a  greater 
advantage  to  the  defense  against  landing  parties  than  to  the 
offense.  Mustard  gas  and  the  like  may  be  sprinkled  from  aero- 
planes, and  while  it  will  not  float  long  on  the  water,  it  will 
float  long  enough  to  smear  any  small  boats  attempting  to  land. 
It  can  be  sprinkled  over  all  the  areas  that  landing  parties  must 
occupy.  Mustard  gas  may  be  placed  in  bombs  or  drums  around 
all  areas  that  are  apt  to  be  used  as  landing  places  and  exploded 
in  the  face  of  advancing  troops. 

Storing  Reserve  Gases  in  Peace.  And  a  word  here  about 
how  long  gases  may  be  stored.  One  of  the  statements  made 
by  opponents  of  chemical  warfare  was  that  gas  is  a  purely 
war  time  project  and  could  not  be  stored  up  in  peace.     We 


382  CHEMICAL  WARFARE 

have  to-day  at  Edgewood  Arsenal  some  1,400  tons  of  poisonous 
gases  not  including  chlorine.  Those  gases  have  been  manu- 
factured, practically  every  ounce  of  them,  for  three  years,  and 
are  yet  in  almost  perfect  condition.  Our  chemists  believe  they 
can  be  kept  in  the  future  for  ten  years  and  perhaps  longer. 
Our  gas  shells  then  will  have  the  life  almost  of  a  modern  battle- 
ship, while  the  cost  of  a  million  will  be  but  a  fraction  of  the 
cost  of  a  battleship.  What  I  have  just  said  applies  particularly 
to  liquid  gases  such  as  phosgene,  chlorpicrin,  and  mustard  gas. 
We  know  that  many  of  the  solids  may  be  kept  for  far  longer 
periods. 

Storing  Gas  Masks.  Our  masks,  too,  we  believe  can  be  kept 
for  at  least  ten  years.  Experience  to  date  indicates  that  rubber 
deteriorates  mainly  through  the  action  of  sunlight  and  mois- 
ture that  cause  oxidation  or  other  change  in  the  crystalline 
structure  of  cured  rubber.  Accordingly,  we  are  putting  up 
masks  to-day  in  hermetically  sealed  boxes.  It  is  thus  evident 
that  we  can  store  a  reserve  of  masks  and  gases  in  peace  the  ^ 
same  as  other  war  materials. 

Use  of  Gas  by  Gas  Troops.  Now  we  come  to  the  use  of  gas 
by  special  gas  troops.  In  the  war,  Gas  Troops  used  4-inch 
Stokes '  mortars  and  8-inch  Livens '  projectors  and  in  a  very  short 
time  would  have  used  a  new  portable  cylinder  for  settiiig  off 
cloud  gas,  using  liquid  gases,  such  as  phosgene.  They  will 
use  these  same  weapons  in  future  wars.  All  of  these  are  short- 
range  weapons,  but  since  the  Livens'  bomb  or  drum  contains 
50  per  cent  of  its  weight  in  gas  while  the  artillery  shell  con- 
tains 10  per  cent,  they  have  an  efficiency  away  beyond  that  of 
artillery  or  any  other  method  of  discharging  gas  except  cloud 
gas.  They  will,  therefore,  produce  more  casualties  than  any 
other  method  known  for  the  amount  of  material  taken  to  the 
front.  These  short-range  weapons  were  developed  by  the  British 
for  trench  use  and.  not  for  open  warfare,  and  yet  our  troops 
developed  methods  with  the  Stokes '  mortars  that  enabled  them 
to  keep  up  with  many  of  the  Infantry  divisions. 

Phosphorus  and  Thermit  Against  Maxjhine  Gun  Nests.  The 
use  of  phosphorus  and  thermit  against  German  machine  gun 
nests  by  the  Gas  Troops  is  well  known.    How  effective  it  was 


RELATION  TO  STRATEGY  AND  TACTICS  383 

not  known  to  so  many.  Phosphorus  and  thermit  were  so 
'used  from  the  early  days  of  the  Marne  fight  in  the  latter  part 
of  July,  1918,  to  the  very  close  of  the  war.  There  is  no  recorded 
instance  where  the  Gas  Troops  failed  to  silence  machine  gun 
nests  once  the  machine  guns  were  located.  In  the  future  Gas 
Troops  will  put  off  the  majority  of  all  cloud  gas  attacks  even 
with  toxic  smoke  candles. 

Necessity  for  Training  in  Peace.  This  is  an  outline  of  the 
subject  of  chemical  warfare.  As  stated  in  the  beginning,  the 
fundamental  underlying  principles  for  the  successful  use  of 
poisonous  gas  is  necessarily  the  same  as  for  any  other  war 
materials.  The  necessity  for  continuous  training  in  peace  is 
just  the  same  with  chemical  warfare  as  with  the  rifle,  the 
machine  gun,  with  field  artillery  or  any  other  weapon  of  war. 
Indeed  it  is  more  so  because  the  use  of  gas  is  so  perfectly 
adaptable  to  night  work.  Men  must  be  taught  to  take  pre- 
cautionary measures  when  so  sleepy,  tired  and  worn  out  that 
tliey  will  sleep  through  the  roar  of  artillery. 

How  Chemical  Warfare  Should  be  Considered.  We  ask  you 
only  to  look  at  the  use  of  chemical  warfare  materials  as  you 
look  at  the  use  of  the  artillery,  infantry,  cavalry,  tanks  or  aero- 
planes. Measure  its  possible  future  use ;  not  simply  by  its  use 
in  the  World  War,  but  by  considering  all  possible  developments 
of  the  future.  Remember  that  its  use  was  barely  four  years 
old  when  the  war  closed,  while  the  machine  gun,  the  latest  type 
of  infantry  weapon,  had  been  known  for  more  than  one-third 
of  a  century.  Chemical  warfare  developments  are  in  the  infant 
stage.  Even  those  on  the  inside  of  chemical  warfare  when  the 
Armistice  was  signed  can  see  to-day  things  that  are  certain  to 
come  that  were  undreamed  of  at  that  time.  This  is  bound  to 
be  so  witli-a  new  weapon. 

To  sum  up,  gas  is  a  universal  weapon,  applicable  to  every 
arm  and  every  sort  of  action.  Since  we  can  choose  gases  that 
are  either  liquid  or  solid,  that  are  irritating  only  or  highly 
poisonous,  that  are  visible  or  invisible,  that  persist  for  days 
or  that  pass  with  the  wind,  we  have  a  weapon  applicable  to 
every  act  of  war  and  for  that  matter,  to  every  act  of  peace. 
But  we  must  plan  its  use,  remembering  there  is  no  middle 


384  CHEMICAL  WARFARE 

ground  in  war,  it  is  success  or  failure,  life  or  death.  Remember 
also  that  training  outruns  production  in  a  great  war,  that 
5,000,000  men  can  be  raised  and  trained  before  they  can  be 
equipped  unless  we  with  proper  foresight  build  up  our  essential 
industries,  keep  up  our  reserve  of  supplies,  and  above  all,  keep 
such  perfect  plans  that  we  can  turn  all  the  wheels  of  peace  into 
the  wings  of  war  on  a  moment  ^s  notice. 


CHAPTER  XXIII 
THE  OFFENSIVE  USE  OF  GAS 

What  Chemical  Warfare  Includes 

Chemical  Warfare  includes  all  gas,  smoke  and  incendiary 
materials  and  all  defensive  appliances,  of  which  the  mask  is  the 
principal  item,  used  by  the  Army.  Some  of  the  items  or  ma- 
terials in  both  offense  and  defense  are  used  by  the  entire  Army, 
while  a  few  are  used  only  by  Chemical  Warfare  troops. 

The  Term  ''Gas" 

The  term  "gas"  is  now  taken  to  include  all  materials  that 
are  carried  to  the  enemy  by  the  air,  after  their  liberation  from 
cylinders,  bombs  or  shell.  It  is  necessary  that  this  broad  use  of 
the  term  ''gas"  be  thoroughly  understood,  because  some  of  these 
materials  are  solids,  while  all  others  are  liquids,  until  liberated 
from  the  containers  at  the  time  of  the  attack.  These  containers 
may  be  special  cylinders  for  cloud  gas  attacks,  special  bombs  for 
Livens'  projectors  and  mortars,  or  artillery  shell,  and  even 
aviation  bombs.  Some  of  the  liquids  which  have  a  very  low 
boiling  point  volatilize  quickly  upon  exposure  to  air,  and  hence 
require  only  enough  explosive. to  open  the  shell  and  allow  the 
liquid  to  escape.  Practically  all  solids  have  to  be  pulverized  by 
a  large  amount  of  high  explosive,  or  driven  off  as  smoke  by 
some  heating  mixture. 

Technical  Nature 

Chemical  warfare,  besides  being  the  newest,  is  the  most  tech- 
nical and  most  highly  specialized  Service  under  the  War  De- 
partment. There  is  no  class  of  people  in  civil  life,  and  no  officers 
or  men  in  the  War  Department,  who  can  take  up  chemical 

385 


386  CHEMICAL  WARFARE 

warfare  successfully  until  they  have  received  training  in  its  use. 
This  applies  not  only  "to  the  use  of  materials  in  attack,  but  to  the 
use  of  materials  for  defense.  Ten  years  from  now  perhaps  this 
will  not  be  true.  It  is  certainly  hoped  that  it  will  not  be.  By 
that  time  the  entire  Army  should  be  pretty  thoroughly  trained 
in  the  general  principles  and  many  of  the  special  features  of 
chemical  warfare.  If  not,  chemical  warfare  cannot  be  used  in 
the  field  with  the  efficiency  and  success  with  which  it  deserves  to 
be  used.  Furthermore,  it  is  believed  that  within  ten  years  the 
knowledge  of  the  gases  used  in  chemical  warfare  will  be  so  com- 
mon through  the  development  of  the  use  of  these  same  materials 
in  civil  life,  that  it  will  not  be  so  difficult,  as  at  the  present  date, 
to  get  civilians  who  are  acquainted  with  Chemical  Warfare  Ser- 
vice materials,    • 

Effectiveness  of  Gas 

Chemical  warfare  materials  were  used  during  the  war  by 
Chemical  Warfare  Service  troops,  by  the  Artillery  and  by  the 
Infantry.  In  the  future  the  Air  Service  and  Navy  will  be  added 
to  the  above  list.  Chemical  warfare,  even  under  the  inelastic 
methods  of  the  Germans,  proved  one  of  the  most  powerful  means 
of  offense  with  which  the  American  troops  had  to  contend.  To 
realizfi__its_effectiveness  we-^ieed  onJyj'emember^tlmt  more  than 
27_outjif_-every_100  casualties  on  the_  field  of  battle  were  from 
gas  alQne.  Unquestionably  many  of  those  who  died  on  the  battle- 
field from  other  causes  suffered  also  from  gas.  No  other  single 
elementjDf  war,  unless,  you  call  powder  a  basic  element,  accounted 
for  so  many  casualties  among  the  American  troops.  Indeed,  it  is 
believed  that  a  greater  number  of  casualties  was  not  inflicted  by 
any  other  arm  of  the  Service,  unless  possibly  the  Infantry,  and 
even  in  that  case  it  would  be  necessary  to  account  for  all  injured 
by  bullets,  the  bayonet,  machine  guns  and  hand  grenades.  This 
is  true,  in  spite  of  the  fact  that  the  German  was  so  nearly  com- 
pletely out  of  gas  when  the  Americans  began  their  offensive  at 
St.  Mihiel  and  the  Argonne,  that  practically  no  gas  casualties 
occurred  during  the  St.  Mihiel  offensive,  and  only  a  very  few 
until  after  a  week  of  the  Argonne  fighting.  Furthermore,  the 
Germans  knew  that  an  extensive  use  of  mustard  gas  against  the 
American  lines  on  the  day  the  attack  was  made,  and  also  on  the 


THE  OFFENSIVE  USE  OF  GAS  387 

line  that  marked  the  end  of  the  first  advance  a  few  days  later, 

would  have  produced  tremendous  casualties.    Judging  from  the 

results  achieved  at  other  times  by  an  extensive  use  of  mustard 

gas,  it  is  believed  that  had  the  German  possessed  this  gas  and 

used  it  as  he  had  used  it  a  few  other  times,  American  casualties  i( 

in  the  Argonne  would  have  been  doubled.    In  fact,  the  advance  1^^ 

might  even  have  been  entirely  stopped,  thus  prolonging  the  war  I  ^ 

into  the  year  1919.  "^^ 

OV 
Humanity  of  Gas 

A  few  words  right  here  about  the  humanity  of  gas  are  not  \ 
out  of  place,  notwithstanding  the  Army  and  the  general  public 
have  now  so  completely  indorsed  chemical  warfare  that  it  is 
believed  the  argument  of  inhumanity  has  no  weight  whatever. 
There  were  three  great  reasons jwhy  chemical  warfare  ,.was  first 
widely  advertised  throughout  the  world  as  inhumane  and  hor- 
rible.   These  reasons  may  be  summed  up  as  follows : 

In  the  first  place,  the  original  gas  used  at  Ypres  in  1915  was 
chlorine,  and  chlorine  is  one  of  a  group  of  gases  known  as 
suffocants — gases  that  cause  death  generally  by  suffocating  the 
patient  through  spasms  of  the  epiglottis  and  throat.  That  is  the 
most  agonizing  effect  produced  by  any  gas. 

The  second  reason  was  unpreparedness.  The  English  had 
no  masks,  no  gas-proof  dugouts,  nor  any  of  the_other_4)ara- 
phernalia  that  was  later  employed  to  protect  against  poisonous 
gas.  Consequently,  the  death  rate  in  the  first  gas  attack  at 
Ypres  was  very  high,  probably  35  per  cent.  As  a  matter  of  fact, 
every  man  who  was  close  to  the  front  line  died.  The  only  ones 
who  escaped  were  those  on  the  edges  of  the  cloud  of  gas  or  so  far 
to  the  rear  that  the  concentration  had  decreased  below  the  deadly 
point.       —— ^ 

The  third  great  reason  was  simply  propaganda.    It  was  good  Af 
war  propaganda  to  impress  upon  everybody  the  fact  that  the      y 
German  was  capable  of  using  any  means  that  he  could  develop    ^f- 
in  order  to  win  a  victory.    He  had  no  respect  for  previous  agree-    ^ 
ments  or  ideas  concerning  warfare.     This  propaganda  kept  up   j^ 
the  morale  and  fighting  spirit  of  the  Allies,  and  was  thoroughly  ^ 
justifiable  upon  that  score,  evenwheirif  led  To  wild  exaggeration^ 

The  chlorine  used  in  the  first  attack  by  the  German  is  the 


\U 


388  CHEMICAL  WARFARE 

least  poisonous  of  the  gases  now  used.  Those  later  introduced, 
such  as  phosgene,  mustard  gas  and  diphenylchloroarsine  are 
from  five  to  ten  times  as  effective. 

The  measure  of  humanity  for  any  form  of  warfare  is  the 
percentage  of  deaths  to  the  total  number  injured  by  the  par- 
ticular method  of  warfare  under  consideration. 

American  Gas  Casualties.    The  t)fficjal  list  of  casualties  in 
^^  battle  as  compiled  by  the  Surgeon  General's  office  covering  all 
\fy     cases-^eprrrted  up  to  September  1,  1919,  is  258,338.     Of  these 
^^"^,752^.^  27.4  per  cent,  were  gas  casualties.    Also  of  the  above 
^^ — casualties  46,519  resulted  in  death,  of  whom  about  1,400  only 
^^  \  were  due  to  gas.     From  these  figures  it  is  readily  deduced  that 
\j^<^^  while  24.85  per  cent  of  all  casualties  from  bullets  and  high  ex- 
plosives resulted  in  death,  only  2  per  cent  of  those  wounded  by 
gas  resulted  in  death.     That  is,  a  man  wounded  on  the  battle 
field  with  gas  had  twelve  times  as  many  chances  of  recovery  as 
the  man  who  was  wounded  with  bullets  and  high  explosives. 

Fundamentals  of  Chemical  Warfare 

Before  taking  up  in  some  detail  the  methods  of  projecting  gas 
upon  the  enemy,  it  is  very  desirable  to  understand  the  funda- 
mentals of  chemical  warfare,  in  so  far  as  they  pertain  to  poison- 
ous gases.  Following  the  first  use  of  pure  chlorine  all  the 
principal  nations  engaged  in  the  war  began  investigations  into  a 
wide  range  of  substances  in  the  hope  of  finding  others  more 
poisonous,  more  easily  produced,  and  more  readily  projected 
upon  the  enemy.  These  investigations  led  to  the  use  of  a  large 
number  of  gases  which  seriously  complicated  manufacture,  sup- 
ply, and  the  actual  use  of  the  gases  in  the  field.  Gradually  a 
more  rational  conception  of  chemical  warfare  led  both  the  Allies 
and  the  enemy  to  restrict  the  numbers  of  gases  to  a  comparative 
few,  and  still  later  to  divide  all  gases  into  three  groups.  Thus 
the  German  divided  his  into  three  groups  known  as  (1)  Green 
Cross,  the  highly  poisonous  non-persistent  gases,  (2)  Blue  Cross, 
or  diphenylchloroarsine,  popularly  known  as  sneezing  gas,  and 
(3)  Yellow  Cross,  highly  persistent  gases,  such  as  mustard  gas. 
In  the  American  Chemical  Warfare  Service  we  have  finally 
divided  all  gases  into  two  primary  groups.     These  groups  are 


THE  OFFENSIVE   USE  OF  GAS  389 

known  as  "Non-persistent"  and  "Persistent."  The  "Non- 
persistent"  gases  are  those  quickly  volatilizing  upon  exposure  to 
the  air,  and  hence  those  that  are  carried  away  at  once  by  air 
currents,  or  that  in  a  dead  calm  will  be  completely  dissipated  into 
the  surrounding  air  in  a  few  hours.  If  sufficient  high  explosive 
be  used  to  pulverize  solids,  they  may  be  used  in  the  same  way, 
and  to  a  large  extent  certain  highly  persistent  liquid  gases  may 
have  their  persistency  greatly  reduced  by  using  a  large  amount 
of  high  explosive,  which  divides  the  liquid  into  a  fine  spray. 
The  "Persistent"  group  constitutes  those  gases  that  are  very 
slowly  volatilized  upon  exposure  to  the  atmosphere.  The  princi- 
pal ones  of  these  now  used  or  proposed  are  mustard  gas  and 
bromobenzylcyanide.  For  purposes  of  economy,  and  hence 
efficiency,  certain  gases,  both  persistent  and  non-persistent,  are 
placed  in  a  third  group  known  as  the  ' '  Irritant  Group. ' '  These 
gases  are  effective  in  extremely  low  concentrations  against  the 
lungs  and  other  air  passages,  or  the  eyes.  Diphenylchloroarsine, 
and  some  other  solids  when  divided  into  minute  particles  by  high 
explosive  or  heat,  irritate  the  nose,  throat  and  lungs  to  such  an 
extent  in  a  concentration  of  one  part  in  ten  millions  of  air  as  to 
be  unbearable  in  a  few  minutes.  The  tear  gases  are  equally 
powerful  in  their  effects  on  the  eyes.  The  irritating  gases  are 
used  to  force  the  wearing  of  the  mask,  which  in  turn  reduces 
the  physical  vigor  and  efficiency  of  the  troops.  This  reduction 
in  efficiency,  even  with  the  best  masks,  is  probably  25  per  cent 
for  short  periods,  and  much  more  if  prolonged  wearing  of  the 
mask  is  forced. 

Efficiency  of  Irritant  Gases 

One  pound  of  the  irritant  gases  is  equal  to  50P  to  1,000  pounds 
of  other  gases  when  forcing  the  wearing  of  the  mask  alone  is  de- 
sired. The  great  economy  resulting  from  their  use  is  thus  appar- 
ent. Due  to  the  rapid  evaporation  of  the  non-persistent  gases  they 
are  used  generally  only  in  dense  clouds,  whether  those  clouds  be 
produced  from  cylinders  or  from  bombs.  These  gases  are  used 
only  for  producing  immediate  casualties,  as  the  necessary  amount 
of  gas  to  force  the  enemy  to  constantly  wear  his  mask  by  the  use 
of  non-persistent  gases  alone  could  not  possibly  be  taken  to  the 
front. 


390  CHEMICAL  WARFARE 

Mustard  gas,  which  is  highly  persistent  and  also  attacks  the 
lungs,  eyes  and  skin  of  the  body,  may  and  will  be  used  to  force 
the  wearing  of  the  mask.  It  has  one  disadvantage  when  it  is 
desired  to  force  immediately  the  wearing  of  the  mask,  and  that 
is  its  delayed  action  and  the  fact  that  it  acts  so  slowly,  and  is 
usually  encountered  in  such  slight  concentrations  that  several 
hours  ^  exposure  are  necessary  to  produce  a  severe  casualty.  For 
these  reasons  the  enemy  may  often  take  chances  in  the  heat  of 
battle  with  mustard  gas,  and  while  himself  becoming  a  casualty, 
inflict  quite  heavy  casualties  upon  opposing  troops  by  continuing 
to  operate  his  guns  or  rifles  without  masks.  A  powerful  tear 
ga.s  on  the  other  hand  forces  the  immediate  wearing  of  the  mask. 

Materiai.  of  Chemical  Warfare  Used  by  C.  W.  S.  Troops 

Chemical  warfare  troops,  in  making  gas  attacks,  use 
cylinders  for  the  cloud  or  wave  attack,  and  the  Livens'  pro- 
jector and  the  4-inch  Stokes'  mortar  for  attacks  with  heavy 
concentrations  of  gas  projected  by  bombs  with  ranges  up  to 
a  mile.  This  distance  will  in  the  future  probably  be  increased 
to  1%  or  1%  miles.  The  original  cylinders  used  in  wave 
attacks  were  heavy,  cumbersome  and  very  laborious  to  install, 
and  notwithstanding  the  wave  attack  was  known  to  be  the 
deadliest  form  of  gas  attack  used  in  the  war,  fell  into  disrepute 
after  the  use  of  gas  became  general  in  artillery  shells  and  in 
special  bombs. 

Cloud  Gas.  The  Americans  at  once  concluded  that  since 
cloud  gas  attacks  were  so  effective,  efforts  should  be  made  to 
make  these  attacks  of  frequent  occurrence  by  decreasing  the 
weight  of  the  cylinders,  and  by  increasing  the  portability  and 
methods  of  discharging  the  cylinders.  As  early  as  March,  1918, 
speciflcations  for  cylinders  weighing  not  more  than  65  pounds, 
filled  and  completely  equipped  for  firing,  were  cabled  to  the 
United  States.  They  would  have  been  used  in  large  numbers  in 
the  campaign  of  1919  had  the  enemy  not  quit  when  he  did. 
Toxic  smoke  candles  that  are  filled  with  solids  driven  off  by 
heat  will  probably  be  the  actual  method  in  the  future  for  put- 
ting off  cloud  attacks.  The  toxic  smoke  candle  is  perfectly  safe 
under  all  conditions  and  can  be  made  in  any  size   desired. 


THE  OFFENSIVE  USE  OF  GAS  391 

Cloud  gas  attacks  will  be  common  in  the  future,  and  all  plans 
of  defense  must  be  made  accordingly.  They  will  usually  be 
made  at  night,  when,  due  to  fatigue  and  the  natural  sleepiness 
which  comes  at  that  time,  men  are  careless,  lose  their  way,  or 
neglect  their  masks,  and  are  thus  caught  unprepared.  Ex- 
perience in  the  war  proved  that  a  wave  attack  always  produced 
casualties  even,  as  several  times  occurred,  when  the  enemy  or  the 
Allied  troops  knew  some  hours  beforehand  that  the  attack  was 
coming.  The  English  estimated  these  casualties  to  be  10  or  11 
per  cent  of  the  troops  exposed. 

Livens'  Projectors.  The  second  most  effective  weapon  for 
using  gas  by  gas  troops  was  and  will  be  the  Livens'  projector. 
This  projector  is  nothing  less  than  the  simplest  form  of  mortar, 
consisting  of  a  straight  drawn  steel  tube  and  a  steel  base  plate. 
As  used  during  the  World  War  by  the  Allies  it  did  not  even 
have  a  firing  pin  or  other  mechanism  in  the  base,  the  electric 
wires  for  firing  passing  out  through  the  muzzle  and  alongside 
the  drum  or  projectile  which  was  small  enough  to  permit  that 
method  of  firing.  These  were  set  by  the  hundreds,  very  close 
behind  or  even  in  front  of  the  front  line  trenches.  They  were 
all  fired  at  the  same  instant,  or  as  nearly  at  the  same  instant  as 
watches  could  be  sjmchronized,  and  firing  batteries  operated.  As 
discussed  on  page  18  these  mortars  were  emplaced  deep  enough 
in  the  ground  to  bring  their  muzzles  practically  level  with  the 
surface.  It  usually  took  several  days  to  prepare  the  attack,  and 
consequently  allowed  an  opportunity  for  the  enemy  to  detect  the 
work  by  aeroplane  photographs  or  by  raids,  and  destroy  the 
emplacements  by  artillery  fire.  It  should  be  added,  however, 
that  notwithstanding  this  apparent  great  difficulty,  very  few 
attacks  were  broken  up  in  that  way.  Nevertheless,  in  line  with 
the  general  policy  of  the  American  troops  to  get  away  from 
anything  that  savored  of  trench  warfare,  and  to  make  the 
fighting  as  nearly  continuous  as  possible  with  every  means  avail- 
able, the  American  Chemical  Warfare  Service  set  at  work  at  once 
to  develop  an  easy  method  of  making  projector  attacks. 

It  was  early  found,  that,  if  the  excavation  was  made  just 
deep  enough  so  that  the  base  plate  could  be  set  at  the  proper 
angle,  the  drums  or  projectiles  were  fired  as  accurately  as  when 
the  projectors  or  mortars  were  set  so  that  the  muzzles  were  level 


392  CHEMICAL  WARFARE 

with  the  surface.  The  time  required  to  emplace  a  given  number 
of  mortars  in  this  way  was  only  about  one-fifth  of  that  required 
for  digging  them  completely  in. 

Coupled  of  course  with  these  proposed  improvements  in 
methods,  studies  were  being  made  and  are  still  being  made 
to  produce  lighter  mortars,  better  powder  charges,  and  better 
gas  checks  in  order  to  develop  the  full  force  of  the  powder. 
Many  improvements  along  this  line  can  be  made,  all  of  which 
will  result  in  greater  mobility,  more  frequent  attacks,  and 
hence  greater  efficiency. 

4-Iiich  Stokes'  Mortar.  The  Stokes'  mortar  is  not  different 
from  that  used  by  the  Infantry,  except  that  it  is  4-inch,  while 
the  Infantry  Stokes'  is  3-inch.  The  4-inch  was  chosen  by  the 
British  for  gas,  as  it  was  the  largest  caliber  that  could  be 
fired  rapidly  and  yet  be  moderately  mobile.  Its  range  of 
only  about  1,100  yards  handicapped  it  considerably.  The  poor 
design  of  the  bomb  was  partly  responsible  for  this.  The  powder 
charges  also  were  neither  well  chosen  nor  well  designed.  It 
is  believed  that  great  improvements  can  be  made  in  the  shape 
of  the  bomb  and  in  the  powder  charge,  which  will  result  in 
much  longer  range  and  high  efficiency,  while  in  no  way  increas- 
ing the  weight  of  the  bomb  or  decreasing  the  rate  of  fire. 
These  last  two  weapons  were  used  during  the  World  War, 
and  will  be  very  extensively  used  in  the  future  for  firing  high 
explosive,  phosphorus,  thermit  and  similar  materials  that  non- 
technical troops  might  handle. 

Since  gas  has  proven  without  the  shadow  of  a  doubt,  that 
it  will  produce  more  casualties  for  an  equal  amount  of  material 
transported  to  the  front  than  any  other  substance  yet  devised, 
^\l  troops  using  short  range  guns  or  mortars  should  be  trained 
to  fire  gas  whenever  weather  conditions  are  right.  When 
weather  conditions  are  not  right,  they  should  fire  the  other 
substances  mentioned.  The  Livens'  projector  with  its  60  pound 
bomb,  of  which  30  pounds  will  be  gas  or  high  explosive,  is 
a  wonderful  gun  up  to  the  limit  of  its  range.  The  bomb,  not  being 
pointed,  does  not  sink  into  the  ground,  and  hence  upon  explod- 
ing exerts  the  full  force  of  high  explosive  upon  the  surround- 
ings, whether  bombs,  pill  boxes,  barbed  wire  or  trenches,  to 
say  nothing  of  personnel. 


h 


THE  OFFENSIVE  USE  OF  GAS  393 

High  Explosive  in  Projectors.  When  these  are  burst  by 
ihe  hundreds  on  a  small  area  everything  movable  is  blotted 
out.  Thus  concrete  machine  gun  emplacements,  lookout  sta- 
tions, bomb-proofs  and  wire  entanglements  are  destroyed, 
trenches  filled  up,  and  the  personnel  annihilated.  This  was 
amply  demonstrated  on  the  few  occasions  when  it  was  actually 
used  at  the  front.  The  American  Infantry,  wherever  they 
saw  it  tried  out,  were  wild  to  have  more  of  it  used.  The  Ger- 
man was  apparently  equally  anxious  to  have  the  use  stopped. 
It  is,  however,  one  of  the  things  that  must  be  reckoned  with 
in  the  future.  It  means  practically  that  No  Man's  Land  in 
the  future  will  be  just  as  wide  as  the  extreme  range  of  these 
crude  mortars — and  here  a  word  of  caution.  While  efforts 
have  been  made  to  increase  the  range  of  these  mortars,  whether 
of  the  Livens'  projector  or  Stokes'  variety,  no  further  increase 
will  be  attempted  when  that  increase  reduces  the  speed  of 
firing  or  the  efficiency  of  the  projectile.  In  other  words  results 
depend  upon  large  quantities  of  material  delivered  at  the  same 
instant  on  the  point  attacked,  and  if  this  cannot  be  obtained 
the  method  is  useless.  For  this  reason  these  mortars  will 
never  be  a  competitor  of  the  artillery.  The  artillery  will  have 
all  that  it  can  do  to  cover  the  field  within  its  range — beyond 
that  reached  by  the  mortars. 

Phosphorus  in  4-Inch  Stokes.  Phosphorus  will  be  used 
largely  by  gas  troops,  but  only  in  the  4-inch  or  other  Stokes' 
mortar  that  may  be  finally  adopted  as  best.  The  Livens'  pro- 
jector carries  too  great  a  quantity,  and  being  essentially  a 
single  shot  gun,  is  not  adapted  to  keeping  up  a  smoke  screen 
by  slow  and  continued  firing,  or  of  being  transported  so  as  to 
keep  up  with  the  Infantry.  Phosphorus  has  also  very  great 
value  for  attacking  personnel  itself.  Any  one  who  has  been 
burned  with  phosphoi'us  or  has  witnessed  the  ease  with  which 
it  burns  when  exposed  to  air,  wet  or  dry,  has  a  most  whole- 
some fear  of  it.  The  result  of  it  in  the  war  showed  that  the 
enemy  machine  gunners  or  other  troops  would  not  stand  up 
under  a  bombardment  of  phosphorus  fired  from  the  4-inch 
Stokes'  mortar — each  bomb  containing  about  seven  pounds. 

Thermit.  Thermit  is  used  in  the  same  way,  and  while 
the   idea   of   molten   metal,   falling   upon   men   and   burning 


394  CHEMICAL  WARFARE 

through  clothing  and  even  helmets,  is  attractive  in  theory,  it 
proved  absolutely  worthless  for  those  purposes  on  the  field 
of  battle.  It  was  found  impossible  to  throw  sufficiently  large 
quantities  of  molten  metal  on  a  given  spot  to  cause  any  con- 
siderable burn.  In  other  words,  the  rapid  spreading  out  and 
cooling  of  the  metal  almost  entirely  ruined  its  effectiveness, 
except  its  effect  on  the  morale.  This  latter,  however,  was 
considerable,  as  one  might  judge  from  seeing  the  thermit  shells 
burst  in  air.  For  this  reason  thermit  may  find  a  limited  use 
in  the  future. 

The  Spread  of  Gas 

Height  of  Gas  Cloud.  The  height  to  which  gas  rises  in  a 
gas  cloud  is  not  exactly  known,  but  it  is  believed  to  be  not 
much  more  than  fifty  feet,  and  then  only  at  a  considerable 
distance  from  the  point  of  discharge.  Moving  pictures  taken 
of  gas  clouds  show  this  to  be  true.  It  is  also  indicated  by 
the  fact  that  pigeons,  which  are  very  susceptible  to  poisonous 
gas,  practically  always  return  to  their  cages  safely  when 
liberated  in  a  gas  cloud.  This  was  a  good  deal  of  a  mystery 
until  it  was  realized  that  the  pigeon  escaped  through  his  rising 
so  quickly  above  the  gas.  This  of  course  would  be  expected 
v/hen  it  is  known  that  practically  all  gases  successfully  used 
were  two  or  more  times  as  heavy  as  air.  Such  gases  rise  only 
by  slow  diffusion,  or  when  carried  upAvards  by  rising  currents. 
The  absence  of  these  upward  currents  at  night  is  one  of  the 
reasons  why  gas  attacks  are  more  effective  at  night  than  dur- 
ing the  day. 

Horizontal  Spread  of  Gas.  Another  important  thing  to 
know  in  regard  to  the  behavior  of  the  wave  of  gas  is  the 
horizontal  spread  of  a  cloud.  If  gas  be  emitted  from  a  cylinder 
the  total  spread  in  both  directions  from  that  point  is  from 
20°  to  30°  or  an  average  of  25°.  This  varies,  of  course,  with 
the  wind.  The  higher  the  wind  the  less  the  angle,  though 
the  variation  due  to  wind  is  not  as  great  as  might  be  expected. 
This  horizontal  spread  of  the  gas  cloud  was  measured  experi- 
mentally, and  the  results  checked  by  aeroplane  pictures 
of  heavy  wave  attacks  over  the  enemy  line.  In  the  latter 
case  the  path  of  the  gas  was  very  closely  indicated  by  the 


THE  OFFENSIVE  USE  OF  GAS  395 

dead  vegetation.  This  vegetation  was  killed  and  bleached 
so  that  it  readily  showed  up  in  aeroplane  photographs.  The 
visibility  of  a  gas  clond  arises  from  the  fact  that  when  a 
large  amount  of  liquid  is  suddenly  evaporated,  the  air  is  cooled 
and  moisture  condensed,  thereby  creating  a  fog.  With  gases 
such  as  mustard  gas  and  others  of  slight  volatility,  a  visible 
cloud  is  not  formed.  For  purposes  of  identification  of  points 
struck  by  shell,  smoke  substances  are  occasionally  added,  or 
a  few  smoke  shell  fired  with  the  gas  shell.  *  As  future  battle 
fields  will  be  dotted  everywhere  with  smoke  clouds,  a  point 
that  will  be  discussed  more  fully  later,  the  firing  of  smoke 
with  gas  shell  will  probably  be  the  rule  and  not  the  exception. 

Requirements  of  Successful  Gas 

If  we  succeed  in  getting  a  poisonous  gas  that  has  no  odor 
it  will  be  highly  desirable  to  fire  it  so  that  it  will  not  be  visible. 
In  that  case  no  smoke  will  be  used.  Carbon  monoxide  is  such 
a  gas,  but  there  are  several  important  reasons  why  it  has  not 
been  used  in  war.  (See  page  190).  These  considerations 
indicate  the  general  requirements  for  a  successful  poisonous 
gas.  If  non-persistent  it  must  be  quickly  volatilized,  or  must 
be  capable  of  being  driven  off  by  heat  or  by  other  means, 
which  can  be  readily  and  safely  produced  in  the  field.  It 
must  be  highly  poisonous,  producing  deaths  in  high  concen- 
trations, and  more  or  less  serious  injuries  when  taken  into 
the  system  in  quantities  as  small  as  one-tenth  of  that  necessary 
to  produce  death.  If  it  has  a  slightly  delayed  action  with  no 
intervening  discomfort,  it  is  still  better  than  one  that  produces 
immediate  discomfort  and  more  or  less  immediate  action.  It 
must  be  readily  compressed  into  a  liquid  and  remain  so  at 
ordinary  temperatures,  with  the  pressure  not  much  above 
25  or  30  pounds  per  square  inch. 

As  a  persistent  gas  it  must  be  effective  in  extremely  low 
concentrations,  in  addition  to  having  the  other  qualities  men- 
tioned above. 

These  general  characteristics  concerning  gases  apply 
whether  used  by  Chemical  "Warfare  troops,  the  Artillery,  the 
Air  Service,  the  Navy,  or  the  Infantry.    In  speaking  of  these 


396  CHEMICAL  WARFARE 

substances  being  used  by  the  Infantry,  it  is  understood  that 
an  ample  number  of  Chemical  Warfare  officers  will  be 
pi'esent  to  insure  that  the  gases  may  not  be  turned  loose  when 
weather  conditions  are  such  that  the  gas  might  drift  back  and 
become  a  menace  to  our  own  troops.  This  is  absolutely  essen- 
tial since  no  troops  who  have  as  varied  duties  to  perform  as 
the  Infantry,  can  be  sufficiently  trained  in  the  technical  side 
of  chemical  warfare  to  know  when  to  put  it  off  on  a  large 
scale  with  safety  and  efficiency. 

Artillery  Use  op  Gas 

The  Artillery  of  the  future  will  probably  fire  more  gas  than 
any  other  one  branch  of  the  Army.  Tliere  are  two  reasons 
for  this — first,  the  large  number  of  guns  now  accompanying 
every  Army,  and  second,  the  long  range  of  many  of  these 
guns.  As  before  indicated,  the  gases  are  adaptable  to  various 
uses,  and  hence  to  guns  differing  both  in  caliber  and  range. 
The  gas  will  be  fired  by  practically  all  guns — from  the  75  mm. 
to  the  very  largest  in  use.  It  is  even  possible  that  if  guns 
smaller  than  the  75  mm.  become  generally  useful  that  certain 
gases  will  be  fired  by  them. 

Efficiency  of  Artillery  Gas  Shell.  It  is  well  to  remember 
in  the  beginning  that  all  artillery  shell  so  far  designed  and 
used,  contain  only  about  10  per  cent  gas,  i.e.,  10  per  cent  of 
the  total  weight  of  shell  and  gas.  It  is  hoped  that  gas  shell 
may  later  be  so  designed  that  a  somewhat  greater  proportion 
of  the  total  weight  of  the  shell  will  be  gas  than  is  now  true. 
This  is  very  desirable  from  the  point  of  efficiency.  As  stated 
above  the  bombs  used  by  Chemical  Warfare  troops  contain 
nearly  50  per  cent  of  their  total  weight  in  gas,  and  hence  are 
nearly  five  times  as  efficient  as  artillery  shell  within  the  limit 
of  range  of  these  bombs.  This  fact  alone  is  enough  to  warrant 
the  use  of  gas  troops  to  their  full  maximum  capacity  in  order 
that  the  artillery  may  not  fire  gas  at  the  ranges  covered. 

Guns  Firing  Persistent  and  Non-Persistent  Gases 

Considering  the  firing  of  non-persistent  and  persistent 
gases,  it  may  be  said  generally  that  non-persistent  gases  will 


THE  OFFENSIVE  USE  OF  GAS  397 

be  fired  only  by  the  medium  caliber  guns  which  are  available 
in  large  numbers.  In  fact,  the  firing  of  non-persistent  gases 
will  be  confined  mainly  to  the  6-inch  or  155  mm.  Howitzer 
and  gun. 

As  our  Army  was  organized  in  France,  and  as  it  is  organ- 
ized at  present,  the  number  of  155  mm.  guns  will  be  greater 
than  all  others  'put  together,  except  the  75  mm.  In  order  that 
a  non-persistent  gas  may  be  most  effective  a  high  concentration 
must  be  built  up  very  quickly.  This  necessitates  the  use  of 
the  largest  caliber  shell  that  are  available  in  large  numbers. 
Of  course,  a  certain  percentage  of  the  gas  shell  of  other  calibers 
may  consist  of  non-persistent  gases  in  order  to  help  out  the 
155  mm.  gun.  This  is  in  accordance  with  the  present  program 
for  loading  gas  shell  and  applies  particularly  to  the  8-inch  and 
240  mm.  Howitzer. 

Few  Ideally  Persistent  or  Non-Persistent  Gases.  Naturally 
there  will  be  very  few  gases  that  are  ideally  non-persistent 
or  ideally  persistent.  The  gi^oups  will  merge  into  one  another. 
Those  on  the  border  line  will  be  arbitrarily  assigned  to  one 
group  or  the.other.  It  might  be  said  definitely,  however,  that 
a  gas  which  will  linger  more  than  six  or  possibly  eight  hours 
under  any  conditions,  except  great  cold,  will  not  be  considered 
non-persistent.  For  reasons  of  efficiency  and  economy  per- 
sistent gases  will  not  be  chosen  unless  they  will  persist  under 
ordinary  conditions  for  two  or  three  days  or  more.  Accord- 
ingly, a  gas  which  would  persist  for  one  day  only  would  have 
to  be  extraordinarily  useful  to  lead  to  its  adoption. 

Firing  Non-Persistent  Gases.  Of  the  non-persistent  gases 
phosgene  is  the  type  and  the  one  most  used  at  present. 
Furthermore,  so  far  as  can  now  be  foreseen,  it  will  continue 
to  be  the  non-persistent  gas  most  used.  It  volatilizes  very 
quickly  upon  the  bursting  of  the  shell.  Accordingly,  in  order 
that  the  shell  fired  at  the  beginning  of  a  gas  ''shoot,"  as  they 
are  generally  referred  to  in  the  field,  shall  still  be  effective 
v/hen  the  last  shell  are  fired,  it  is  necessary  that  the  whole 
number  be  fired  within  two  to  three  minutes.  The  temperature 
and  velocity  of  the  wind  both  affect  this.  If  it  be  in  a  dead 
calm,  the  time  may  be  considerably  extended ;  if  in  a  consider- 
able wind,  it  must  be  shortened.    Another  important  considera- 


398  CHEMICAL  WARFARE 

tion  requiring  the  rapid  firing  of  non-persistent  gases  is  the 
fact  that  nearly  all  masks  thoroughly  protect  against  phosgene 
and  similar  gases.  It  is  accordingly  necessary  to  take  the 
enemy  unawares  and  gas  him  before  he  can  adjust  his  mask; 
otherwise,  practically  no  harm  will  result.  From  the  con- 
siderations previously  mentioned,  these  *'gas  shoots"  are 
usually  made  at  night  when,  as  before  stated,  carelessness, 
sleepiness  and  the  resulting  confusion  of  battle  conditions 
always  insure  more  casualties  than  firing  gas  in  the  daytime. 

Firing  Persistent  Gases.  The  persistent  gases  will  be  fired 
by  all  caliber  guns,  but  to  a  less  extent  by  the  155  mm.  than 
by  the  other  calibers.  Persistent  gases  must  be  sufficiently 
effective  in  low  concentrations  to  act  more  or  less  alone.  If 
it  be  desirable  to  fill  an  atmosphere  over  a  given  area  with 
mustard  gas,  the  firing  may  extend  for  two  or  three,  or  even 
five  or  six  hours  and  all  shell  still  act  together.  The  same  is 
true  of  bromobenzylcyanide.  This,  then,  permits  the  minimum 
number  of  guns  to  be  used  in  firing  these  persistent  gases. 
Inasmuch  as  they  persist  and  force  the  wearing  of  the  mask, 
they  are  available  for  use  in  long-range,  large-caliber  guns 
for  interdiction  firing  on  cross-roads,  in  villages,  and  on  woods 
that  afford  hiding  places,  as  well  as  on  other  similar  concentra- 
tion points. 

Firing  Irritant  Gases.  The  irritant  gases  will  be  fired  by 
the  various  caliber  guns,  in  the  same  manner  as  the  persistent 
and  non-persistent  gases.  We  will  have  non-persistent  irritant 
gases  and  persistent  irritant  gases.  They  are,  however,  con- 
sidered as  a  group  because  they  are  used  for  harassing  pur- 
poses, due  to  their  efficiency  in  forcing  the  wearing  of  the 
mask. 

Before  the  signing  of  the  Armistice,  the  General  Staff, 
A.  E.  F.,  had  authorized,  beginning  January  1,  1919,  the  filling 
of  25  per  cent  of  all  shell  with  Chemical  Warfare  materials. 
The  interpretation  there  given  to  shell  was  that  it  included 
both  shrapnel  and  high  explosive. 

Of  the  field  guns  in  use,  the  75  mm.  will  be  best,  up  to  the 
limit  of  its  range,  for  persistent  gases  such  as  mustard  gas, 
and  the  tear  gas,  bromobenzylcyanide.  A  considerable  number, 
however,  were  filled  with  non-persistent  gases  and  probably 


rTHE  OFFENSIVE  USE  OF  GAS  399 

will  continue  to  be  so,  since,  due  to  the  very  large  number 
of  75  mm.  guns  available,  they  can  be  used  to  add  greatly 
at  times  to  the  amount  of  non-persistent  gas  that  can  be  fired 
upon  a  given  point. 

Use  of  Gas  by  the  Aviation   Service 

No  gas  was  used  by  aeroplanes  in  the  World  War.  Many 
rumors  were  spread  during  the  latter  part  of  the  war  to  the 
effect  that  the  Germans  had  dropped  gas  here  or  there  from 
aeroplanes.  Every  such  report  reaching  the  Chemical  Warfare 
Service  Headquarters  was  run  down  and  in  every  case  was 
found  to  be  incorrect.  However,  there  was  absolutely  no 
reason  for  not  so  using  gas,  except  that  the  German  was 
afraid.  In  the  early  days  of  the  use  of  gas  he  did  not  have 
enough  gas,  nor  had  he  developed  the  use  of  aeroplanes  to 
the  point  where  it  would  have  seemed  advisable.  When,  how- 
ever, he  had  the  aeroplanes  the  war  had  not  only  begun  to  go 
against  him,  but  he  had  become  particularly  fearful  of  gas  and 
of  aeroplane  bombing. 

It  does  not  seem  to  be  generally  known,  but  it  is  a  fact, 
that  after  three  or  four  months'  propaganda  he  made  a  direct 
appeal  to  the  Allies  to  stop  the  use  of  gas  sometime  during 
the  month  of  March,  1918.  This  propaganda  took  the  form 
of  an  appeal  by  a  Professor  of  Chemistry  who  had  access  to 
Switzerland,  to  prevent  the  annihilation  of  the  Allied  forces 
by  a  German  gas  that  was  to  make  its  appearance  in  1918. 
This  German  professor  claimed  that,  while  favoring  the  Ger- 
mans winning  the  war,  he  had  too  much  human  sympathy  to 
desire  to  see  the  slaughter  that  would  be  caused  by  the  use 
of  the  new  gas.  The  Allies  in  the  field  felt  that  this  was 
simply  an  expression  of  fear  and  that  he  did  not  have  such 
a  gas.  The  Germans  were  accordingly  informed  that  the  Allies 
would  not  give  up  the  use  of  gas.  Later  events  proved 
these  conclusions  to  be  absolutely  correct.  The  German  evi- 
dently felt  that  the  manufacturing  possibilities  of  the  Allies 
would  put  them  in  a  more  predominant  position  with  gas  than 
with  anything  else.    In  that  he  was  exactly  correct. 

The   use   of  gas   by  aeroplanes  will  not   differ   from  its 


400  CHEMICAL   WARFARE 

use  in  artillery  or  by  Chemical  Warfare  Troops.  Non- 
persistent  gases  may  be  dropped  on  the  field  of  battle,  upon 
concentration  points,  in  rest  areas,  or  other  troop  encamp- 
ments to  produce  immediate  casualties.  Persistent  gases  will 
be  dropped  particularly  around  cross-roads,  railroad  yards, 
concentration  points  and  encampments  that  cannot  be  reached 
by  the  artillery.  The  sprinkling  of  persistent  gases  will  be  one 
of  the  best  ways  for  aeroplanes  to  distribute  gas. 

It  might  be  said  here  that  the  aviation  gas  bomb  will  be 
highly  efficient,  inasmuch  as  it  has  to  be  only  strong  enough 
to  withstand  the  low  pressure  of  the  gas  and  ordinary  hand- 
ling, whereas  artillery  shell  must  be  strong  enough  to  with- 
stand the  shock  of  discharge  in  the  gun. 

Infantry  and  Gas  Warfare 

When  one  suggests  the  possibility  of  the  infantry  handling 
gas,  it  is  at  once  argued  that  the  infantry  is  already  over- 
loaded. That  is  true,  but  in  the  future,  as  in  the  past,  the 
infantryman  will  increase  or  decrease  his  load  of  a  given 
material  just  as  its  efficiency  warrants.  If  he  finds  that  gas 
will  get  casualties  and  help  him  win  victories  more  readily 
than  an  equal  weight  of  any  other  material,  he  will  carry 
gas  material.  A  study  of  the  articles  of  equipment  abandoned 
by  10,000  stragglers  in  the  British  Army  picked  up  during  the 
great  German  drive  towards  Amiens  in  March,  1918,  illus- 
trates this  very  clearly.  Of  the  equipment  carried  by  these 
stragglers,  more  than  6,000  had  discarded  their  rifles.  The 
helmets  were  thrown  away  to  a  somewhat  less  extent,  but  the 
gas  mask  had  been  thrown  away  by  only  800  out  of  the  10,000. 
Now  the  gas  mask  is  not  a  particularly  easy  thing  to  carry, 
nor  was  the  English  type  comfortable  to  wear,  but  the  English 
soldier  had  learned  that  in  a  gas  attack  he  had  no  chance 
whatever  of  escape  if  his  gas  mask  failed  him.  Accordingly, 
he  hung  on  to  the  mask  when  he  had  discarded  nearly  every- 
thing else  in  his  possession.  The  same  thing  will  be  true  of 
any  gas  equipment  if  it  proves  its  worth. 


THE  OFFENSIVE  USE  OF  GAS  401 

Smoke  and  Incendiary  Materials 

So  far  nothing  has  been  said  in  regard  to  smoke  or  incen- 
diary materials.  This  has  been  due  to  the  fact  that  their 
use  is  not  dependent  upon' weather  conditions  to  anything  near 
the  extent  that  gas  is.  Second,  the  smokes,  not  being  poison- 
ous, are  not  a  danger  to  our  own  troops,  although  they  may 
hamper  movements  and  add  to  the  difficulty  of  taking  a  posi- 
tion, if  used  improperly.  Of  the  two  classes  of  materials, 
smoke  and  incendiary,  smoke  materials  may  be  said  to  be  at 
least  a  thousand  times  as  important  as  the  incendiary  materials. 
A  material  that  will  burst  into  flame  when  a  shell  is  opened 
or  that  will  scatter  balls  of  burning  fire  appeals  to  the  popular 
imagination,  and  yet  actual  results  achieved  by  such  materials 
on  the  field  of  battle  have  been  almost  nil.  About  the  only 
results  worth  while  achieved  by  incendiary  materials  have 
been  in  occasionally  firing  ammunition  dumps  and  more  fre- 
quently, setting  fire  to  warehouses  and  other  storage  places. 
This  will  undoubtedly  continue  in  the  future. 

Flame  Thrower 

Of  the  incendiary  materials  the  least  valuable  is  the  flame 
tlirower.  In  the  Chemical  Warfare  Service  it  has  been  the 
habit  for  a  long  while  not  to  mention  the  flame  thrower  at 
all,  unless  questions  were  asked  about  it.  It  is  mentioned 
here  to  forestall  the  questions.  Even  the  German,  who  invented 
it  and  who,  during  the  two  years  of  trench  warfare,  had  full 
opportunity  for  developing  its  use,  finally  came  to  using  it 
largely  as  a  means  of  executing  people  that  he  did  not  want 
to  shoot  himself.  Men  falling  in  that  class  were  equipped 
with  flame  throwers  and  sent  over  the  top.  The  German  knew, 
as  did  the  Allies,  that  each  man  with  a  flame  thrower  became 
a  target  for  every  rifle  and  machine  gun  nearby.  The  flame 
thrower  is  very  quickly  exhausted  and  then  the  one  equipped 
with  it  has  no  means  of  offensive  action,  and  in  addition,  is 
saddled  with  a  heavy  load,  hampering  all  movements,  whether 
to  escape  or  to  advance. 


402  CHEMICAL  WARFARE 

Inflammable  Materials 

There  will  probably  be  some  use  for  materials  such  as 
metallic  sodium,  spontaneously  inflammable  oils,  etc.,  that  will 
burst  into  flame  and  burn  when  exposed  to  the  air,  though 
white  phosphorus  is  probably  equal,  and  in  most  cases  vastly 
superior  to  anything  else  so  far  suggested.  Phosphorus  burns 
with  an  unquenchable  flame  when  exposed  to  the  air,  whether 
wet  or  dry.  It  is  of  great  value  for  screening  purposes,  and 
for  use  against  the  enemy's  troops.  The  German  did  not  use 
phosphorus  simply  because  he  did  not  have  it,  just  as  he  did 
not  use  helium  in  his  observation  balloons  because  he  did  not 
have  it. 

The  value  of  phosphorus  was  just  beginning  to  be  realized 
slightly  when  the  Americans  entered  the  war,  while  its  full 
value  was  not  appreciated  even  by  the  American  troops  when 
the  war  closed. 

The  work  of  the  First  Gas  Regiment  with  phosphorus 
against  machine  gun  nests  proved  how  valuable  it  is  against 
the  enemy's  troops.  It  proved  also  its  tremendous  value  as  a 
screen. 

The  Chemical  "Warfare  Service  was  prepared  to  fill  a  great 
number  of  artillery  shell  with  phosphorus,  but  due  to  the 
failure  of  our  shell  program  to  mature  before  the  Armistice, 
phosphorus  was  not  used  by  American  artillery  to  any  appre- 
ciable extent. 

Smoke  Used  by  Everyone 

Smoke  will  be  used  by  every  fighting  arm  of  the  Service 
in  practically  every  battle,  both  by  day  and  by  night.  If  you 
have  ever  tried  on  a  target  range  to  shoot  at  a  target  that  was 
just  beginning  to  be  obscured  by  a  fog,  you  will  recognize 
the  difficulty  of  hitting  anything  by  firing  through  an  impene- 
trable smoke  screen.  It  is  simply  a  shot  in  the  dark.  Future 
battles  will  witness  smoke  formed  by  smoke  candles  that  are 
kept  in  the  trenches  or  carried  by  the  troops,  by  smoke  from 
bursting  artillery  shell  and  rifle  grenades,  by  smoke  from 
aeroplane  bombs  and  possibly  even  from  what  is  known  as 
the  smoke  knapsack.     The  knapsack  produces  a  very  dense 


THE  OFFENSIVE  USE  OF  GAS  403 

white  smoke  and  very  economically,  but  will  probably  not 
be  much  used.  This  is  because,  notwithstanding  its  efficiency, 
the  knapsack  cannot  be  projected  to  a  distance,  that  is,  the 
smoke  screen  is  generated  on  the  person  carrying  the  knap- 
sack. On  the  other  hand  the  great  value  of  phosphorus  is  that 
it  can  be  fired  to  great  distances  in  rifle  grenades  or  artillery 
shell,  and  dropped  from  aviation  bombs.  The  smoke  screen 
is  thus  established  in  front  of  the  object  it  is  desired  to  cut 
off,  whether  it  be  a  battery  of  artillery,  an  advancing  wave 
of  infantry,  or  a  lookout  station.  Thus  smoke,  for  screening 
purposes  alone,  will  be  used  to  a  tremendous  extent.  It  will 
also  be  used  in  conjunction  with  gas. 


Smoky  Appearance  op  Gas  Cloud 


4 


Due  to  the  smoky  appearance  of  an  ordinary  gas  cloud  and 
to  the  coming  use  of  poisonous  smokes,  no  one  on  the  field 
of  battle  in  the  future  will  ever  be  certain  that  any  given 
smoke  cloud  is  not  also  a  poisonous  cloud  until  he  has  actually 
tested  it.  And  there  lies  an  opportunity  for  the  most  intense 
study  and  for  the  greatest  use  of  the  proverbial  American 
ingenuity  that  war  has  ever  furnished. 

In  the  variations  that  can  be  played  with  smoke  containing 
gas,  or  not  containing  gas,  with  smoke  hurled  long  distances 
by  the  artillery  or  dropped  from  aeroplanes,  the  possibilities 
indeed  are  unlimited.  Every  officer  will  need  to  study  the 
<  possibilities  of  smoke,  both  in  its  use  against  him  and  in 
his  use  of  it  against  the  enemy.  He  can  probably  save  more 
casualties  among  his  own  troops  by  the  skillful  use  of  smoke 
than  by  any  other  one  thing  at  his  command.  On  the 
other  hand,  the  unskilled  use  of  smoke  on  the  part  of  one 
side  in  a  battle  may  lead  to  very  great  casualties  in  proportion 
to  those  of  the  enemy  should  the  latter  use  his  smoke  skill- 
fully.   This  is  a  subject  that  deserves  deep  and  constant  study. 

Protection  by  Smoke  Clouds 

Smoke  in  the  future  will  be  the  greatest  protective  device 

^  available  to  the  soldier.     It  shuts  out  not  only  the  view  in 

daylight,  but  the  searching  of  ground  at  night  by  search- 


404  CHEMICAL   WARFARE 

lights,  by  star  bombs  or  other  means  for  illuminating  the  battle- 
field. It  has  already  been  used  extensively  by  the  Navy  and 
undoubtedly  will  be  used  far  more  extensively  in  the  future. 

Shell  Markings 

Modern  artillery  shell  have  distinctive  colors  for  high 
explosive,  for  shrapnel,  for  incendiary  materials,  and  for  gases. 
A  grayish  color  has  been  adopted  as  the  general  color  of 
the  paint  on  all  gas  shells,  bombs  and  cylinders.  In  addition 
a  system  of  colored  bands  has  been  adopted.  These  bands  are 
white  to  indicate  poisonous  non-persistent  substances,  and  red — 
persistent.  Yellow  is  used  to  indicate  smoke.  With  any  given 
combination  of  red  and  white  and  yellow  bands,  the  artillery- 
man at  the  front  can  tell,  at  a  glance,  whether  the  gas  is  non- 
persistent  or  whether  it  is  persistent,  and  also  whether  or  not 
it  contains  smoke.  There  will  be  secondary  markings  on  each 
shell  which,  to  the  trained  Chemical  AVarfare  Service  officer, 
will  indicate  the  particular  gas  or  gases  in  the  shell.  These 
markings  however,  will  be  inconspicuous  and  no  attempt  will 
be  made  to  give  the  information  to  the  soldier  or  even  to  the 
average  officer  firing  gas. 

These  secondary  markings  are  for  the  purpose  of  enabling 
the  Chemical  Warfare  Service  officers  in  charge  to  use  certain 
gases  for  particular  uses  in  those  comparatively  rare  cases 
when  sufficient  gas  is  on  hand  and  sufficient  time  available  to 
enable  such  a  choice  to  be  made. 


CHAPTER  XXIV 
DEFENSE    AGAINST    GAS 

(From  the  Field  Point  of  View) 

The  best  defense  against  any  implement  of  war  is  a  vigorous 
offense  with  the  same  implement.    This  is  a  military  axiom  that 
cannot  be  too  often,  or  too  greatly  emphasized,  though  like  other 
axioms  it  cannot  be  applied  too  literally.    It  needs  a  proper  in- 
terpretation— the  interpretation  varying  with  time  and  circum- 
stances.   Thus  in  gas  warfare,  a  vigorous  offense  with  gas  is  the 
best  defense  against  gas.  This  does  not  mean  that  the  enemy 's  gas 
can  be  ignored.    Indeed,  it  is  more  important  to  make  use  of  all 
defensive  measures  against  gas  than  it  is  against  any  other  form      1 
of  attack.     Gas  being  heavier  than  air,  rolls  along  the  ground,^^'    r 
filling  dugouts,   trenches,   woods   and  jyalleys — ^just  the  places  |  ^^  y 
that'^  are  safest   from   bullets   and   high   explosives.      There  it       ^^ 
remains  for  hours  after  it  has  blown  away  in  the  open,  and,  ^^\i( 
since  the  very  air  itself  is  poisoned,  it  is  necessary  not  only  that 
protection  be  general  but  that  it  be  continuous  during  the  whole 
time  the  gas  is  present. 

Earliest  Protective  Appliances 

The  earliest  protection  against  gas  was  the  crudest  sort  of  a 
mask.  The  first  gas  used  was  chlorine  and  since  thousands  of 
people  in  civil  life  were  used  to  handling  it,  many  knew  that 
certain  solutions,  as  hj^posulfite  of  soda,  would  readily  destroy  it. 
They  also  knew  that  if  the  breath  could  be  drawn  through 
material  saturated  with  those  solutions,  the  chlorine  would  be 
destroyed.  Thus  it  was  that  the  first  masks  were  simple  cotton, 
or  cotton  waste  pads,  which  were  dipped  into  hyposulfite  of  soda 
solutions  and  applied  to  the  mouth  and  nose  during  a  gas  attack. 

405 


406  CHEMICAL  WARFARE 

These  pads  were  awkward,  unsanitary,  and,  due  to  the  long  inter- 
vals between  gas  attacks,  were  frequently  lost,  while  the  solution 
itself  was  often  spilled  or  evaporated.  The  net  i:esult  of  all  this 
was  poor  protection  and  disgust  with  the  so-called  masks. 

Design  of  New  Masks 

After  using  these,  or  similar  poor  excuses  for  a  mask,  for  a 
few  weeks',  the  British  designed  what  was  known  as  the  PH 
helmet.  In  a  gas  attack  the  sack  was  pulled  over  the  head  and 
tucked  under  the  blouse  around  the  neck,  the  gas  tight  fit  being 
obtained  by  buttoning  the  blouse  over  the  ends  of  the  sack.  This 
PH  helmet  was  quite  successful  against  chlorine  and,  to  a  much 
less  extent,  against  phosgene,  a  new  gas  introduced  during  the 
spring  of  1916. 

But  it  was  warm  and  stuffy  in  summer — the  very  time  when 
gas  is  used  to  the  greatest  extent — while  the  chemicals  in  the 
cloth  irritated  the  face  and  eyes,  especially  when  combined  with 
some  of  the  poisonous  gases. 

Probably  as  a  result  of  experience  with  oxygen  apparatus  in 
mine  rescue  work.  Colonel  Harrison  suggested  making  a  mask 
of  which  the  principal  part  was  a  box  filled  with  chemicals  and 
carried  on  the  chest.  A  flexible  tube  connected  the  box  with  a 
mouth-piece  of  rubber.  Breathing  was  thus  through  the  mouth 
and  in  order  to  insure  that  no  air  would  be  breathed  in  through 
the  nose,  a  noseclip  was  added. 

This,  of  course,  cared  for  the  lungs,  but  did  not  protect  the 
eyes.  Their  protection  was  secured  by  making  a  facepiece  of 
rubberized  cloth  with  elastics  to  hold  it  tight  against  the  face. 
The  efficiency  of  this  mask  depends,  then,  first  upon  the  ability 
of  the  facepiece  to  keep  out  lachrymatory  gases  which  affect  the 
eyes,  and,  second,  upon  a  proper  combination  of  chemicals  in  the 
box,  to  purify  the  air  drawn  into  the  lungs  throilgh  the  mouth- 
piece.    (Details  are  given  in  Chapter  XII). 

Protection  Against  Smoke  \ 

While  the  charcoal  and  soda  lime  granules  furnished  an 
adequate  protection  against  all  known  true  gases,  they  did  not 
furnish  protection   against   certain   smokes   or   against   minute 


DEFENSE  AGAINST  GAS  407 

particles  of  liquid  gas.  Since  certain  smokes,  as  stannic  chloride, 
though  not  deadly,  are  so  highly  irritating  as  to  make  life  un- 
bearable, it  early  became  necessary  to  devise  means  for  keeping 
them  from  going  through  the  masks.  This  was  done  in  the  first 
masks  by  adding  a  sufficient  thickness  of  cotton  batting.  The 
cotton  was  usually  placed  in  three  layers  alternating  with  the 
charcoal  and  granules,  as  it  was  thought  the  latter  would  be  held 
in  place  better  by  that  means. 

Some  time  after  stannic  chloride  came  into  use  the  Germans 
started  firing  shells  containing  a  small  quantity  of  diphenyl- 
cliloroarsine,  popularly  known  as  ** Sneezing  Gas.'*  Protection 
against  this  is  discussed  in  Chapter  XVIII. 

Choice  of  Masks  for  U.  S.  Troops 

When  it  became  necessary,  with  the  creation  of  a  Chemical 
Warfare  Service  in  France  in  August,  1917,  to  decide  upon  a 
mask  for  American  troops,  there  were  available  for  purchase 
two  types — the  British  type  and  the  French  M-2.  The  French 
M-2  consisted  essentially  of  32  layers  of  cloth  impregnated  with 
various  chemicals,  through  which  the  air  was  breathed  both  in 
and  out.  This  mask  was  quite  effective  against  ordinary  field 
concentrations  of  most  gases,  but  was  utterly  inadequate  to  care 
for  the  high  concentration  of  phosgene  obtained  in  the  front 
line  from  cloud  gas  or  from  projector  gas  attacks.  It  was  also 
poor  against  chloropicrin.  The  M-2  was,  however,  very  light  and 
easy  to  carry  and  moreover  was  deemed  sufficient  to  protect 
against  concentrations  of  cloud  gas  even,  at  points  more  than 
five  miles  distant  from  the  front  line. 

Furthermore,  it  was  felt  desirable  at  first  to  have  an  auxiliary 
or  emergency  mask  in  addition  to  the  principal  one,  for  use  in 
case  the  principal  mask  was  worn  out  or  damaged.  Accordingly 
both  types  of  masks  were  adopted  and  the  day  after  Fries  took 
charge  of  the  Chemical  Warfare  Service,  A.E.F.,  on  August 
22,  1917,  100,000  of  each  were  purchased,  although  there  were 
then  only  ten  or  twelve  thousand  American  troops  in  France 
requiring  masks.  Later  additional  masks  of  both  kinds  were 
purchased  to  tide  over  the  American  troops  until  a  sufficient 
quantity  of  the  British  type  masks  could  be  manufactured  in 


408  CHEMICAL  WARFARE 

the    United    States.      The    total    of    British    masks    purchased 
amounted  to  about  700,000, 

However,  within  a  comparatively  short  time  after  American 
troops  got  into  the  front  line  it  was  realized  that  a  second  mask, 
inferior  in  protection  to  the  first,  was  highly  undesirable.  Dur- 
ing a  gas  attack  men  seemed  to  acquire  an  uncontrollable  desire 
to  shift  from  one  mask  to  the  other.  This  shifting  in  nearly 
every  case  resulted  in  a  casualty.  We  then  came  rapidly  to  the 
conclusion  that  one  mask  only  should  be  furnished,  and  that 
one  the  liest  that  could  be  made,  and  then  to  impress  upon  the 
soldier  the  fact  that  his  life  depended  upon  the  care  he  took  of 
his  mask.  This  proved  to  be  an  entirely  sound  conclusion,  as 
the  number  of  men  gassed  through  injuries  to  the  mask  was 
comparatively  small.  An  interesting  proof  of  the  value  the 
soldier  placed  upon  his  mask  was  shown  by  the  articles  of  equip- 
ment thrown  away  by  10,000  British  stragglers  in  the  great 
German  offensive  of  March,  1918.  Of  the  articles  thus  thrown 
away  the  gas  mask  came  at  the  foot  of  the  list,  with  only  800 
missing.  The  steel  helmet  is  said  to  have  come  next  with  about 
4,000  missing. 

Sizes  of  Faces  for  Masks 

"When  adopting  the  British  respirator  in  August,  1917,  it 
was  decided  that  the  American  face  as  well  as  the  American 
stature  was  probably  larger  than  the  English.  Accordingly 
inquiry  was  made  in  regard  to  the  sizes  of  masks  issued  to  the 
Canadians  as  it  was  thought  probable  they  required  a  greater 
proportion  of  the  larger  size  masks  than  did  the  English.  When 
prescribing  the  relative  quantities  of  each  size  of  mask  to  be 
furnished  Americans,  the  Canadian  requirements  were  taken  as 
a  base  but  with  the  larger  sizes  increased  slightly  over  the 
Canadian  requirements.  As  a  matter  of  fact  even  these  in- 
creases proved  considerably  too  small,  so  that  the  numbers  in  the 
two  sizes  above  normal  had  to  be  finally  more  than  doubled. 

Objections  to  German  Type  Mask 

The  American  Gas  Service  felt  from  the  beginning  that  a 
design  which  attached  the  box  of  chemicals  to  the  facepiece  was 


DEFENSE  AGAINST  GAS  409 

unsound  in  principle  (this  design  was  used  in  the  German  mask 
and  in  the  French  A.  R.  S.  masks),  since  it  did  not  allow  proper 
flexibility  for  increasing  the  size  of  the  box  to  care  for  new 
gases.  Furthermore,  the  weight  of  the  box  during  movement 
caused  the  facepiece  to  swing  slightly  from  side  to  side.  This 
interfered  with  vision  and  tended  to  lift  the  facepiece  away 
from  the  face  and  allow  gas  to  enter.  That  the  objections  of  the 
American  Gas  Service  to  this  type  were  correct  was  proved  by 
the  difficulty  encountered  toward  the  end  of  the  war  by  both  the 
French  and  the  Germans  in  trying  to  provide  a  suitable  filter 
for  protection  against  particulate  clouds  and  the  smokes,  such  as 
stannic  chloride  and  diphenylchloroarsine. 

Struggle  Between  Mask  and  Gas 

As  between  the  mask  and  poisonous  gases,  we  have  the  old 
struggle  of  the  battleship  armor  against  the  armor-piercing  pro- 
jectile. While  the  armor-piercing  projectile  has  always  had  a 
little  the  better  of  the  game,  it  is  just  the  reverse  with  gases. 
The  gas  mask  has  always  been  just  a  little  better  than  the  gases, 
so  that  very  few  casualties  have  occurred  through  failure  of  the 
mask  itself.  This  margin  of  safety  has  never  been  any  too  great, 
and  that  we  have  had  a  margin  at  all  is  due  to  the  energy,  skill  and 
enthusiasm  of  those  developing  and  manufacturing  masks  in 
England,  France,  and  particularly  in  the  United  States. 

However,  the  mask  at  the  best  is  uncomfortable,  causes  some 
loss  of  vigor,  and  even  with  the  very  best  American  masks  there 
is  some  loss  in  vision.  The  wearing  effect  on  troops  results 
mostly  from  the  increased  resistance  to  breathing.  Accordingly 
a  tremendous  amount  of  study  and  effort  was  made  to  decrease 
this  breathing  resistance.  In  the  English  type  masks  this 
resistance  was  equal  to  the  vacuum  required  to  raise  a  column 
of  w^ater  about  four  and  one-half  inches.  Adding  the  sulfite 
paper  to  protect  against  diphenylchloroarsine  increased  this 
resistance  by  about  one  inch.  This  put  a  heavy  burden  on  the 
wearer  of  the  mask  whenever  it  was  necessary  for  him  to  do  any 
manual  labor  while  wearing  it.  In  addition  earlier  masks  left  a 
good  deal  to  be  desired  in  the  way  of  reducing  resistance  by 
proper  sized  tubes,  angles  and  valves  through  which  the  air  was 


410  CHEMICAL  WARFARE 

drawn.  This  was  much  more  easily  overcome  than  reducing  the 
resistance  through  the  chemicals  and  charcoal  and  the  materials 
for  protection  against  diphenylchloroarsine.  In  the  latest  type 
canister,  devised  after  long  trials  for  the  American  forces,  this 
resistance  was  brought  down  to  about  two  inches  of  water.  "What 
this  reduction  in  resistance  means  no  one  knows  except  one  who 
has  worn  the  old  mask  with  its  mouth-piece  and  four  to  six 
inches'  resistance  and  has  then  replaced  that  mask  for  one 
through  which  he  breathes  naturally  with  only  two  inches' 
resistance. 

Design  of  New  American  Mask 

The  American  Gas  Service  felt  from  the  beginning  that  the 
mouth-piece  and  noseclip  must  be  abandoned  and  bent  every 
effort  toward  getting  a  mask  perfected  for  that  purpose.  The 
English  opposed  this  view  fiercely  for  nearly  a  year.  This 
position  on  the  part  of  the  English  was  more  or  less  natural. 
They  developed  their  mask  in  the  beginning  for  protection 
against  cloud  gas.  In  those  days  the  opposing  trenches  were 
close  together.  Moreover,  front  line  trenches  were  quite  strongly 
manned.  The  result  was  that  a  large  number  of  men  were 
exposed  to  a  very  high  concentration  of  gas,  but — and  highly 
important — for  a  short  period  only.  Inasmuch  as  the  German 
feared  this  cloud  gas  even  more  than  the  English  there  was  no 
danger  of  his  attacking  in  it.  The  English  rules  of  conduct 
during  a  gas  attack  called  for  all  movement  to  stop  and  for 
every  man  to  stand  ready  until  the  cloud  passed.  Accordingly, 
the  man  was  breathing  the  easiest  possible  and  hence  did  not 
suffer  particularly  from  the  resistance. 

With  the  advent  of  mustard  gas,  however,  the  whole  general 
scheme  of  protection  changed.  Mustard  gas,  as  is  well  known, 
is  effective  in  extremely  low  concentrations  and  has  very  great 
persistency.  In  dry  warm  weather  mustard  gas,  scattered  on 
the  ground  and  shrubbery,  will  not  be  fully  evaporated  for  two 
to  three  days  and  accordingly  will  give  off  vapors  that  not  only 
burn  the  lungs  and  eyes  but  the  soft,  moist  parts  of  the  skin  as 
well.  In  cool,  damp  weather  the  gas  remains  in  dangerous 
quantity  for  a  week  and  occasionally  longer.  Since  this  gas,  in 
liquid  form,  evaporates  too  slowly  for  use  in  gas  clouds,  it  is 


DEFENSE  AGAINST  GAS  411 

used  altogether  in  bombs  and  shells.  Accordingly  it  could  be 
expected  to  be  and  actually  is  fired  at  all  ranges  from  the  front 
line  to  nearly  eight  miles  back  of  that  line.  Hence,  with  the 
coming  of  mustard  gas,  the  need  for  protection  changed  from 
high  protection  for  a  short  period  to  moderate  protection  for  very 
long  periods.  Indeed,  mustard  gas  makes  it  necessary  for  men 
to  wear  masks  just  as  long  as  they  remain  in  an  area  infected 
with  it.  There  is  still  occasional  need  for  high  protection  for 
short  periods,  but  with  the  increase  in  the  efficiency  of  charcoal 
alone,  it  is  found  that  the  amount  of  charcoal  and  chemicals  in 
the  canister  can  be  very  greatly  reduced  and  still  maintain 
sufficient  protection  for  the  high  concentrations  encountered  in 
cloud  gas  and  projector  attacks. 

Exhaustion  and  Malingering 

It  seems  physically  impossible  for  the  ordinary  man  to  wear 
the  British  mask  with  its  mouth-piece  and  noseclip  more  than 
six  to  eight  hours  and  vast  numbers  are  unable  to  even  do  that. 
How  many  thousands  of  casualties  were  suffered  through  men 
losing  their  mental  balance  from  exhaustion  and  the  discomfort 
of -the  mouth-piece  and  noseclip  no  one  knows.  Such  men  tore 
off  the  mask,  stating  that  they  would  rather  die  than  endure  the 
torture  of  wearing  it  longer.  Furthermore,  the  poor  vision  of 
this  mask  led  to  the  habit  of  taking  the  facepiece  off  while  still 
leaving  the  mouth-piece  and  noseclip  in  place.  This  gave  pro- 
tection to  the  lungs,  but  exposed  the  eyes,  and  as  mustard  gas 
affects  the  eyes  very  readily  this  alone  led  to  thousands  of  casu- 
alties. There  was  another  interesting  side  to  this  situation.  The 
malingerer  who  wanted  to  get  out  of  the  front  line  and  was  will- 
ing to  take  any  action,  however  cowardly,  to  achieve  that  end, 
deliberately  removed  the  facepiece  and  thus  suffered  gassing  of 
the  eyes.  The  effect  of  mustard  gas  soon  became  so  well  known 
that  the  malingerer  knew  gassing  of  the  eyes  never  resulted  in 
death  or  permanent  loss  of  sight.  With  the  new  type  of 
American  mask,  the  protection  of  eyes  and  lungs  depends  solely 
upon  the  fit  around  the  face  and  no  such  playing  with  the  mask 
can  be  done. 

"Without  going  into  further  details  in  regard  to  masks  it  is 


412  CHEMICAL  WARFARE 

sufficient  to  state  that  at  the  end  the  Americans  had  produced  a 
mask  thoroughly  comfortable,  giving  complete  protection  against 
gases  and  smoke  clouds,  and  one  that  was  easy  to  manufacture  on 
the  huge  scale  (fifty  to  seventy-five  thousand  per  day)  which  was 
necessary  to  provide  masks  for  an  army  of  three  to  four  million 
men  in  the  field. 

Protection  in  War  is  Relative  Only 

Napoleon  is  credited  with  saying  ''In  order  to  make  an 
omelet,  it  is  necessary  to  break  some  eggs.''  Every  student  of 
war  realizes  that  casualties  cannot  be  avoided  in  battle  and  yet 
one  American  Staff  Officer  went  so  far  as  to  refuse  to  use  gas 
offensively  unless  the  Chemical  Warfare  Service  could  absolutely 
guarantee  that  not  a  single  American  casualty  could  occur  under 
any  circumstances.  This  same  idea  early  got  into  the  heads  of 
the  laboratory  workers  on  masks.  They  seemed  to  feel  that  if  a 
single  gas  casualty  occurred  through  failure  of  the  mask,  their 
work  would  be  a  failure  or  at  least  they  would  be  open  to  severe 
criticism.  Accordingly  efforts  were  made  to  perfect  masks  and 
to  perfect  protection  regardless  of  the  discomfort  imposed  upon 
the  wearer  of  the  mask.  This  idea  was  very  difficult  to  eradicate. 
The  laboratory  worker  who  accustoms  himself  to  experiment  with 
a  particular  thing  forgets  that  he  develops  an  ability  to  endure 
discomfort,  that  is  not  possible  of  attainment  by  the  ordinary 
man  in  the  time  available  for  his  training. 

Furthermore,  if  the  need  for  such  training  can  be  avoided  it 
is  of  course  highly  desirable.  This  applies  to  the  mouth-piece  of 
the  British  respirator;  to  elastics  that  cause  undue  discomfort 
to  the  face ;  to  the  noseclip  and  to  the  large  boxes  that  cause  too 
great  resistance  to  breathing. 

It  may  be  taken  as  a  general  rule  that  when  protection 
requires  so  much  effort  or  becomes  so  much  of  a  burden  that  the 
average  man  cannot  or  will  not  endure  it,  it  is  high  time  to  find 
out  what  the  average  man  will  stand  and  then  provide  it  even 
if  some  casualties  result.  Protection  in  battle  is  always  relative. 
A  man  who  cannot  balance  protection  against  legitimate  risk  has 
no  business  passing  on  arms,  equipment  or  tactics  to  be  used  in 
battle. 


DEFENSE  AGAINST  GAS  413 

Training 

Bitter  experience  taught  the  Allies  as  well  as  the  Americans 
that  no  matter  how  efficient  the  gas  mask  and  other  defensive 
appliances,  they  would  not  take  the  place  of  thorough  and  con- 
stant training.  One  of  the  greatest  difficulties  at  first  was  to  get 
American  troops  to  realize  that  a  thing  as  invisible  as  gas,  with  in 
many  cases  no  offensive  smell  and  producing  no  immediate  dis- 
comfort, could  be  deadly.  Nothing  but  constant  drill  and  con- 
stant reiteration  of  these  dangers  could  get  this  fact  impressed 
on  them.  Indeed  it  never  was  impressed  sufficiently  in  any  of 
the  earlier  divisions  of  American  troops  in  the  line  to  prevent 
their  taking  such  chances  that  each  division  suffered  heavy  loss 
on  one  or  more  occasions  from  gas  attacks. 

A  great  deal  of  emphasis  had  been  placed  by  the  English 
upon  the  adjustment  of  the  mask  in  the  shortest  possible  time, 
this  time  having  been  officially  set  at  six  seconds  after  the  alarm. 
The  Americans  in  adopting  the  mask  in  toto  naturally  had  to 
adopt  the  rules  for  adjusting  it  and  wearing  it.  Experience,  how- 
ever, taught  them  in  a  few  months  that  the  effort  to  attain  too 
great  speed  was  dangerous.  It  tended  to  rattle  the  soldier  and 
to  result  in  poor  adjustment  of  the  mask,  both  of  which  led  to 
causalties.  Accordingly  in  the  latest  instructions  for  defense 
against  gas  all  reference  to  six  seconds  was  eliminated  and 
emphasis  placed  on  the  necessity  of  accurate  adjustment  of 
the  mask.  Inasmuch  as  any -man,  practically  without  effort  or 
previous  drill,  can  hold  his  breath  for  twenty  seconds,  the  need 
for  great  speed  in  adjusting  the  mask  is  not  apparent. 

Holding  the  Breath 

The  first  regulations  and  those  in  general  use  up  to  near 
the  close  of  hostilities,  prescribed  that  the  soldier  should  hold 
his  breath  and  adjust  his  mask.  It  seemed  impossible  to 
overcome  the  natural  inference  that  ''holding  the  breath" 
meant  first  the  drawing  of  a  full  breath.  This  was  obviously 
highly  dangerous  if  gas  were  actually  present  before  the 
alarm  was  heard,  as  was  often  the  case  with  projector  and 
artillery   gas  shell  attacks.     The  change  was  then  made  to 


414  CHEMICAL  WARFARE 

the  phrase  '*Stop  Breathing  and  Stay  Stopped  until  the  Mask 
is  Carefully  and  Accurately  Adjusted/' 

Psychology  in  Training 

While  the  importance  of  impressing  upon  the  soldier  the 
danger  of  gas  was  early  appreciated  it  was  deemed  necessary 
not  to  make  him  unduly  afraid  of  the  gas.  However,  as  gas 
defense  training  in  our  Army  got  a  big  start  over  gas  offense 
training,  this  became  a  matter  of  very  great  importance.  In 
fact,  due  to  a  variety  of  causes,  training  in  the  offensive  use 
of  gas  was  not  available  for  any  troops  until  after  their  arrival 
in  France.  This  resulted  in  officers  and  men  looking  upon 
the  gas  game,  so  far  as  they  were  individually  concerned,  as 
one  of  defense  only.  Accordingly  after  their  arrival  in  France 
it  became  verj^  difficult  not  only  to  get  some  of  our  officers 
to  take  up  the  offensive  use  of  gas  but  even  to  get  them  to 
permit  its  use  along  the  front  they  commanded. 

Notwithstanding  all  the  care  taken  in  training  Americans 
in  gas  defense  there  arose  an  undue  fear  of  the  gas  that  had 
to  be  overcome  in  order  to  get  our  troops  to  attack  close 
enough  to  their  own  gas  to  make  it  effective.  This  applied 
to  the  use  of  gas  by  artillery  as  well  as  to  its  use  by  gas  troops. 
However,  it  should  be  said  that  in  every  instance  where  gas  was 
once  used  on  an  American  front  all  officers  in  the  Division, 
or  other  unit,  affected  by  it  were  always  thereafter  strongly 
in  favor  of  it. 

German  Problems  in  Gas  Training 

The  Germans  also  had  serious  troubles  of  their  own  over 
the  psychology  of  gas  training.  As  stated  elsewhere  they 
were  using  mustard  gas  nearly  eleven  months  before  the  Allies 
began  using  it.  During  that  time,  for  purposes  of  morale,  if 
not  sheer  boastfulness,  the  Germans  told  their  men  that  mus- 
tard gas  could  not  be  made  by  the  Allies ;  that  it  was  by  far 
the  worst  thing  the  war  had  produced— and  in  that  statement 
they  were  correct— and  that  they  would  win  the  war  with 
it — in  which  statement  they  were  far  from  correct.  When  the 
Allies  began  sending  it  back  to  them  they  had  to  reverse  their 


DEFENSE  AGAINST  GAS  415 

teachings  and  tell  their  men  that  mustard  gas  was  no  worse 
than  anything  else,  that  they  need  not  be  afraid  of  it  and  that 
their  masks  and  other  protective  appliances  gave  full  protec- 
tion against  it.  They  thus  had  a  problem  in  psychology  which 
they  never  succeeded  in  fully  solving.  Indeed  there  is  no 
question  but  that  the  growing  fear  of  gas  in  the  minds  of  the 
German  is  one  of  the  reasons  that  prompted  him  to  his  early 
capitulation. 

^v     Gas  at  Night 

In  the  early  dayb  it  was  very  difficult  to  get  officers  to 
realize  the  absolute  necessity  of  night  drill  in  the  adjustment 
of  the  mask.  For  various  reasons,  including  surprise,  gas 
attacks  were  probably  eighty  to  ninety  per  cent  of  the  time 
carried  out  at  night.  Under  such  conditions  confusion  in  the 
adjustment  of  the  mask  is  inevitable  without  a  great  deal  of 
practice  before  hand,  especially  for  duty  in  trenches  with 
narrow  spaces  and  sharp  projecting  corners.  There  are  numer- 
ous instances  of  men  waking  up  .and  getting  excited,  who  not 
only  gassed  themselves,  but  in  their  mad  efforts  to  find  their 
masks,  or  to  escape  from  the  gas,  knocked  others  down,  dis- 
arranging their  masks  and  causing  the  gassing  of  from  one 
to  three  or  four  additional  men.  The  confusion  inherent  in 
any  gas  attack  was  heightened  in  the  latter  stages  of  the  war 
by  heavy  shrapnel  and  high  explosive  bombardments  that 
accompanied  nearly  all  projector  and  cloud  gas  attacks  for  that 
very  purpose.  The  bombardment  was  continued  for  three  or 
four  hours  to  cause  exhaustion  and  removal  of  the  mask  and 
to  prevent  the  removal  of  the  gassed  patients  from  the  gassed 
area.  y 

Y      Detection  of  Gases 

Efforts  were  made  by  the  enemy  and  by  all  the  Allies 
throughout  the  war  to  invent  a  mechanical  detector  that  would 
show  when  gas  was  present  in  dangerous  quantities.  "While 
scores,  perhaps  hundreds,  of  these  were  invented  none  proved 
simple,  quick,  or  certain  enough  in  action  to  make  their  adop- 
tion desirable.  In  every  case  it  was  necessary  to  rely  on  the 
sense  of  smell.     Thus  it  was  that  as  the  war  wore  on,  more 


416  CHEMICAL  WARFARE 

and  more  attention  was  given  to  training  officers  and  non- 
commissioned officers  to  detect  various  kinds  of  gases  in 
dangerous  quantities  by  the  sense  of  smell. 

In  the  American  Gas  Defense  School  for  officers  this  was 
done  wholly  by  using  captured  German  gases.  This  was 
because  certain  gases  have  quite  different  smells,  depending 
upon  the  impurities  in  the  gas  and  also  upon  the  solvents 
sometimes  mixed  with  them.  Thus  the  German  mustard  gas 
has  a  mustard  smell,  while  the  Allies  mustard  gas,  due  to  a 
slight  difference  in  the  method  of  manufacture,  has  a  very 
perfect  garlic  odor.  Not  only  must  officers  and  men  who 
handle  gas  training  know  the  smell  of  the  various  gases,  but 
they  must  know  when  the  concentration  of  each  is  high 
enough  to  be  dangerous.  This  is  not  easy  to  learn  because 
the  strength  of  the  various  gases  in  dangerous  concentrations 
varies  through  wide  limits.  Not  only  does  the  strength  of 
the  gases  vary  and  the  sharpness  of  the  odors  accordingly, 
but  the  mingling  of  poisonous  gases  with  other  gases  from  high 
explosive  and  shrapnel  tends  .to  obscure  these  odors  and  make 

them  more  difficult  of  detection. 

■\ 

Deceptive  Gases 

A  great  deal  of  thought  was  given  toward  the  end  of 
the  war  to  the  subject  of  deceptive  gases  which  could  by 
powerful  or  peculiar  odors  mask  the  dangerous  gases.  This 
masking  was  to  deceive  the  enemy  when  dangerous  gases  were 
present  or  to  admit  an  attack  without  masks  while  the  enemy 
was  wearing  his  through  thinking  there  was  a  dangerous  gas 
when  as  a  matter  of  fact  none  existed. 

In  gas  warfare,  the  German,  as  well  as  the  Allies,  was 
exercising  his  ingenuity  in  devising  new  and  startling  methods 
of  making  gas  attacks.  A  well  known  trick  with  the  German 
was  to  fire  gases  for  several  days,  particularly  against  green 
troops,  in  concentrations  so  slight  as  to  do  no  harm.  When 
he  felt  that  he  had  lulled  those  troops  to  a  sense  of  the  ineffec- 
tiveness of  his  gas,  he  sent  over  a  deadly  concentration.  In 
spite  of  the  warning  that  this  was  what  was  happening,  he 
often  achieved  too   great  a  success.     Before  the  war  closed, 


DEFENSE  AGAINST  GAS  417 

however,  the  American  was  beginning  to  out-think  and  out-wit 
the  German  in  this  method  of  warfare. 

Mustard  Gas  Burns 

With  the  advent  of  mustard  gas  which  burned-  the  body, 
a  new  and  serious  difficulty  in  protection  arose.  At  first  it 
was  thought  mustard  gas  burned  only  when  the  liquid  from 
the  bursting  shell  actually  splashed  on  the  clothing  or  skin. 
This  was  unfortunately  soon  found  to  be  not  true.  The  gas 
itself  rapidly  penetrates  clothing  and  burns  the  skin  even  when 
the  concentration  of  the  gas  is  very  low.  Probably  the  ma- 
jority of  burns  from  mustard  gas  arose  from  concentrations 
of  gas  consisting  of  less  than  one  part  of  gas  to  five  hundred 
thousand  of  air.  Furthermore,  the  gas  is  fully  fifty  per  cent 
cumulative  in  its  effects,  that  is,  in  extremely  low  concentra- 
tions over  a  period  of  hours  it  will  produce  more  than  fifty 
per  cent  the  effect  that  a  far  higher  concentration  would 
produce  in  a  relatively  shorter  time. 

The  Allies  were  not  long  in  discovering  that  oilcloth 
afforded  very  complete  protection  against  mustard  gas.  The 
ordinary  oilcloth,  however,  was  too  thick,  too  hot  and  too 
heavy  for  general  use.  Experiments  soon  showed  that  cloth 
thoroughly  impregnated  with  boiled  linseed  oil  would  give 
protection.  In  order  to  make  this  protection  more  perfect 
a  certain  amount  of  paraffin  was  added.  All  this  made  the 
clothing  air-tight,  rather  stiff  and  always  uncomfortable.  Not- 
withstanding these  discomforts,  hundreds  of  thousands  of 
oiled  suits,  and  as  many  pairs  of  oiled  gloves  were  made  and 
issued  to  artillery  troops,  and  to  troops  especially  charged 
with  handling  mustard  gas  shells,  or  to  those  employed  in 
destroying  mustard  gas  in  shell  holes  by  spreading  chloride 
of  lime  over  them. 

The  importance  of  protection  against  mustard  gas  burns 
led  to  extensive  researches  being  made  with  a  view  to  finding 
a  cloth  which  would  be  comfortable  and  porous  and  while 
stopping  mustard  gas  would  yet  be  sufficiently  durable  and 
comfortable  to  be  issued  to  infantry  troops  as  well  as  to 
artillery  and  other  special  troops.    This,  it  is  understood,  had 


418  CHEMICAL  WARFARE 

been  achieved,  just  prior  to  the  Armistice.  Still  more  desir- 
able would  be  the  discovery  of  a  chemical  substance  which 
could  be  applied  to  all  uniforms  and  Army  clothing  and  thus 
protect  the  regulation  clothing  against  the  penetration  of 
mustard  gas,  and  thereby  avoid  carrying  extra  clothing  for 
that  special  purpose. 

Protecting  Troops  by  Moving  Them  From  Infected  Areas 

As  soon  as  it  was  fully  realized  that  mustard  gas  persisted 
for  several  days  it  was  decided  to  run  complete  reliefs  of 
men  into  and  out  of  areas  that  had  been  heavily  shelled  with 
mustard  gas,  or  better  still,  where  practicable,  to  completely 
evacuate  the  area.  Inasmuch  as  the  gas  is  dangerous  to 
friend  and  foe  alike,  this  method  was  comparatively  safe  and 
was  used  to  a  very  considerable  extent.  With  the  warfare 
of  movement  that  existed  over  most  of  the  active  front 
throughout  the  season  of  1918,  this  moving  of  troops  out  of 
infected  areas  became  highly  important  and,  when  skillfully 
done,  often  resulted  in  a  great  saving  of  troops  and  at  the  same 
time  prevented  the  enemy  from  receiving  any  particular  tac- 
tical advantage  from  his  mustard  gas  attacks. 

There  was  one  very  excellent  example  of  this  a  few  miles 
to  the  northwest  of  Chateau-Thierry  prior  to  the  counter- 
offensive  of  July  18,  1918.  At  that  time  the  Germans  heavily 
shelled  with  mustard  gas  four  or  five  small  woods  and  two 
or  three  villages.  It  was  necessary  for  the  men  to  stay  in 
these  woods  during  the  day,  as  they  afforded  the  only  protec- 
tion obtainable  from  machine  guns,  shrapnel  and  high 
explosive.  At  the  time  this  occurred  American  gas  officers 
generally  understood  the  necessity  of  getting  troops  out  of 
a  mustard  gas  infected  area.  Accordingly  all  began  searching 
for  places  safe  from  the  mustard  gas.  In  one  particular  in- 
stance the  gas  officer  of  a  regiment  discovered  that  a  portion 
of  the  woods  his  men  were  in  was  free  from  the  gas,  and 
the  regimental  commander,  promptly  following  his  advice, 
moved  his  troops  into  the  free  area.  As  a  result  of  this  prompt 
action  the  regiment  had  only  four  light  gas  casualties,  although 
all  told  there  were  several  hundred  mustard  gas  casualties 


DEFENSE  AGAINST  GAS  419 

in  this  attack,  the  number  per  thousand  generally  being  from 
ten  to  twenty  times  that  of  the  thousand  men  just  mentioned. 


\ 


Mixing  Poisonous  Gases 


On  this  as  well  as  other  occasions  the  Germans  fired  some 
diphosgene  and  Blue  Cross  (Sneezing  gas),  as  well  as  mustard 
gas.  This  added  to  the  difficulty  of  determining  areas  free 
from  the  latter.  In  the  future  such  mixing  of  poisonous  gases 
may  always  be  expected  and,  in  addition,  gases  which  have 
no  value  other  than  that  of  masking  the  poisonous  ones  will 
be  fired.  While  with  practically  all  gases  except  mustard  gas 
a  man  is  comparatively  safe  while  breathing  a  concentration 
very  noticeable  to  the  sense  of  smell,  the  only  safe  rule  with 
mustard  gas  is  to  consider  as  dangerous  any  concentration 
that  can  be  smelled. 

For  the  reason  that  this  gas  persists  longer  in  calm  areas, 
woods  are  always  to  be  avoided,  where  practicable,  and  also, 
since  all  gases,  being  heavier  than  air,  tend  to  roll  into  depres- 
sions and  valleys,  they  should  be  avoided.  There  have 
been  a  number  of  authentic  cases  where  batteries  in  hollows 
or  valleys  suffered  severely  from  mustard  gas,  while  troops 
on  nearby  knolls  or  ridges  were  comparatively  free,  though 
the  difference  in  the  amount  of  shelling  of  the  two  places 
vv'as  not  noticeable. 

Of  great  importance  with  all  gases  is  the  posting  of  a 
sufficient  number  of  sentries  around  men  sleeping  within  the 
range  of  gas  shell.  The  worst  projector  gas  attack  against 
tlie  Americans  was  one  where  the  projectors  were  landed 
among  a  group  of  dugouts  containing  men  asleep  without 
sentries.  The  result  was  a  very  heavy  casualty  list,  coupled 
with  a  high  death  rate,  the  men  being  gassed  in  their  sleep 
before  they  were  awakened. 

\),  Destruction  op  Mustard  Gas 

Prior  to  the  introduction  of  mustard  gas  all  that  was 
necessary  to  get  rid  of  gas  was  to  thoroughly  ventilate  the 
spot.  Thus  in  trenches  and  dugouts,  fires  were  found  to  be 
very  efficient,  simply  because  they  produced  a  circulation  of 


420  CHEMICAL  WARFARE 

air.  In  the  early  days,  among  the  British,  the  Ayrton  fan, 
a  sort  of  canvas  scoop,  was  used  to  throw  the  gas  out  of  the 
trenches.  While  this  was  taken  up  in  the  American  Service, 
it  did  not  become  very  important,  since  it  was  found  that, 
under  ordinary  atmospheric  conditions,  natural  ventilation 
soon  carried  the  gas  out  of  the  trench  proper,  while  fires  in 
dugouts  were  far  more  efficient  than  the  fans.  Likewise  the 
Ayrton  fan  smacked  too  much  of  trench  warfare  which  had 
reached  a  condition  of  *' stalemate" — a  condition  that  never 
appealed  to  the  Americans  and  a  condition  that  it  is  hoped 
never  will. 

With  mustard  gas,  however,  conditions  were  entirely 
changed.  This  liquid  having  a  very  high  boiling  point  and 
evaporating  very  slowly,  remains  for  days  in  the  earth  and 
on  vegetation  and  other  material  sprinkled  with  it.  This  was 
particularly  true  in  shell  holes  where  the  force  of  the  explosion 
drove  the  gas  into  the  earth  around  the  broken  edges  of  the 
hole.  While  many  substances  were  experimented  with,  that 
which  proved  best  and  most  practical  under  all  conditions, 
v/as  chloride  of  lime.  This  was  used  to  sprinkle  in  shell  holes, 
en  floors  of  dugouts  and  any  other  places  where  the  liquid 
might  be  splashed  from  bursting  shells.  It  was  also  found 
very  desirable  to  have  a  small  box  of  this  at  the  entrance  to 
each  dugout,  so  that  a  person  who  had  been  exposed  to  mustard 
gas  could  thoroughly  coat  his  shoes  with  it  and  thus  kill  tlie 
mustard  gas  that  collected  in  the  mud  on  the  bottom  and  sides 
of  his  shoes. 

Carrying  Mustard.  Gas  on  Clothing 

There  are  many  instances  where  the  occupants  of  dugouts 
were  gassed  from  the  gas  on  the  shoes  and  clothing  of  men 
entering  the  dugout.  Not  only  Avere  occupants  of  dugouts  thus 
gassed  but  a  number  of  nurses  and  doctors  were  gassed  while 
working  in  closed  rooms  over  patients  suffering  from  mustard 
gas  poisoning.  Even  under  the  conditions  of  warfare  existing 
where  the  Americans  were  generally  in  action,  the  quantity 
of  chloride  of  lime  required  amounted  to  several  hundred  tons 
per  month  which  had  to  be  shipped  from  the  United  States. 


DEFENSE  AGAINST  GAS  421 

Chloride  of  lime  was  also  very  convenient  to  have  at  hand 
around  shell  dumps  for  the  purpose  of  covering  up  leaky  shells, 
though  rules  for  handling  mustard  gas  shells  usually  prescribed 
that  they  be  fired  and  where  that  was  not  practicable  to  bury 
them  at  least  five  feet  under  the  surface  of  the  ground.  This 
depth  was  not  so  much  for  the  purpose  of  getting  rid  of  the 
gas  as  it  was  to  get  the  shell  so  deep  into  the  ground  that  it 
would  not  be  a  danger  in  any  cultivation  that  might  later 
take  place. 

Mustard  Gas  in  Cold  Weather        "^ 

Much  was  learned  toward  the  end  of  the  war  about  ways 
of  getting  through  or  around  areas  infected  with  mustard  gas. 
For  instance,  if  mustard  gas  be  fired  when  the  weather  is  in 
the  neighborhood  of  freezing  or  somewhat  below,  it  will  remain 
on  the  ground  at  night  with  so  little  evaporation  as  not  to 
be  dangerous.  The  same  will  be  true  during  the  day  time 
if  the  weather  is  cloudy  as  well  as  cold.  If,  however,  the  days 
are  bright  and  the  niglits  cold,  mustard  gassed  areas  can  be 
safely  crossed  by  troops  at  night  provided  care  is  taken  in 
brush  and  buslies  to  protect  the  feet  and  clothing  from  the 
liquid  splashed  on  bushes.  If  the  sun  comes  out  warm  in 
the  morning  such  areas  may  be  quite  dangerous  for  three  to 
four  hours  following  sun-up  and  indeed  for  the  greater  part 
of  the  day.  Quite  a  large  number  of  casualties  were  ascribed 
to  this  fact  in  the  heavy  attack  on  the  British  front  west 
of  Cambrai  just  prior  to  the  great  German  drive  against 
Amiens,  March  21,  1918. 

Degassing  Units  \^ 

Since  mustard  gas  has  a  greatly  delayed  action  it  was 
found  that  if  men  who  had  been  exposed  to  it  could  be  given 
a  thorougli  bath  with  soap  and  water  within  a  half  hour  or 
even  a  full  hour,  the  mustard  gas  burns  would  be  prevented 
or  very  greatly  reduced  in  severity.  Accordingly  degassing 
units  were  developed  consisting  essentially  of  a  5  ton  truck 
with  a  1200  gallon  water  tank,  fitted  with  an  instantaneous 
heater   and  piping  to   connect  it  to  portable   shower  baths. 


422  CHEMICAL  WARFARE 

Another  truck  was  kept  loaded  with  extra  suits  of  undercloth- 
ing and  uniforms.  These  degassing  units  were  to  be  provided 
at  the  rate  of  two  per  division.  Then,  in  the  event  of  a  mus- 
tard gas  attack  anywhere  in  the  division,  one  of  these  units 
would  be  rushed  to  that  vicinity  and  the  men  brought  out 
of  the  line  and  given  a  bath  and  change  of  clothing  as  soon 
as  possible.  At  the  same  time  they  were  given  a  drink  of 
bicarbonate  of  soda  water  and  their  eyes,  ears,  mouth  and 
nasal  passages  washed  with  the  same. 

Protecting  Food  from  Mustard  Gas  \ 

It  was  very  early  learned  that  mustard  gas,  or  minute 
particles  of  the  liquid  gas  settling  on  food,  caused  the  stomach 
to  be  burned  if  the  food  were  eaten,  just  as  the  eyes,  lungs 
and  skin  of  the  body  are  burned  from  gas  in  the  air.  This 
made  it  necessary  then  to  see  that  all  food  liable  to  exposure 
to  mustard  gas  attacks  was  protected,  and  tarred  paper  for 
box  linings  or  tops  was  found  by  the  Gas  Service  to  furnish 
one  of  the  cheapest  and  most  available  means  of  doing  this. 

Alarm  Signals  \ 

Numerous,  indeed,  were  the  devices  invented  at  one  time 
or  another  with  which  to  sound  gas  alarms.  The  English 
early  devised  the  Strombos  horn,  a  sort  of  trumpet  operated 
by  compressed  air  contained  in  cylinders  carried  for  that 
purpose.  Its  note  is  penetrating  and  can  be  heard,  under 
good  conditions,  for  three  or  four  miles.  When  cloud  gas 
attacks,  which  occurred  only  at  intervals  of  two  to  four 
months,  were  the  only  gas  attacks  to  be  feared,  it  was  easy 
enough  to  provide  for  alarm  signals  by  methods  as  cumbersome 
and  as  technically  delicate  as  the  Strombos  horn. 

With  the  advent  of  shell  gas  in  general,  and  mustard  gas 
in  particular,  the  number  of  gas  attacks  increased  enormously. 
This  made  it  not  only  impossible,  but  inadvisable  also,  to 
furnish  sufficient  Strombos  horns  for  all  gas  alarms,  as  gas 
shell  attacks  are  comparatively  local.  In  such  cases,  if  the 
Strombos  horn  is  used  to  give  warning,  it  causes  troops  who 
are  long  distances  out  of  the  area  attacked  to  take  precautions 


DEFENSE  AGAINST  GAS  423 

against  gas  with  consequent  interference  with  their  work  or 
fighting. 

To  meet  these  local  conditions  metal  shell  cases  were  first 
hung  up  and  the  alarm  sounded  on  them.  Later  steel  triangles 
were  used  in  the  same  way.  At  a  still  later  date  the  large 
policeman's  rattle,  well  known  in  Europe,  was  adopted  and 
following  that  the  Klaxon  horn.  As  the  warfare  of  movement 
developed  the  portability  of  alarm  apparatus  became  of  prime 
importance.  For  those  reasons  the  Klaxon  horn  and  the  police 
rattle  were  having  a  race  for  popularity  when  the  Armistice 
was  signed. 

A  recent  gas  alarm  invention  that  gives  promise  is  a  small 
siren-like  whistle  fired  into  the  air  like  a  bomb.  It  is  fitted 
with  a  parachute  which  keeps  it  from  falling  too  rapidly  when 
the  bomb  explodes  and  sets  it  free.  Its  tone  is  said  to  be  very 
penetrating  and  to  be  quite  effective  over  an  ample  area. 
Since  future  gas  alarm  signals  must  be  efficient  and  must  be 
portable,  the  lighter  and  more  compact  they  can  be  made  the 
better;  hence  the  desirability  of  parachute  whistles  or  similar 
small  handy  alarms. 

IssuESTG  New  Masks 

One  of  the  problems  that  remained  unsolved  at  the  end 
of  the  war  was  how  to  determine  when  to  issue  new  boxes,  or 
canisters,  for  masks.  One  of  the  first  questions  asked  by  the 
soldier  is  how  long  his  mask  is  good  in  gas,  and  how  long 
when  worn  in  drill  where  there  is  no  gas.  This  information 
is  of  course  decidedly  important.  Obviously,  however,  it  is 
impossible  to  tell  how  long  a  canister  will  last  in  a  gas  attack, 
unless  the  concentration  of  gas  is  known — that  is,  the  life 
of  the  box  is  longer  or  shorter  as  the  concentration  of  gas 
is  weak  or  heavy. 

A  realization  of  this  need  led  mask  designers  to  work  very 
hard,  long  before  the  necessity  for  comfort  in  a  mask  was  as 
fully  realized  as  it  was  at  the  end  of  the  war,  to  increase 
the  length  of  life  of  the  canister.  To  get  longer  life  they 
increased  the  chemicals  and  this  in  turn  increased  the  breath- 
ing resistance,  thereby  adding  to  the  discomfort  of  the  soldier 


424  CHEMICAL  WARFARE 

when  wearing  the  mask.  Finally,  however,  it  was  found  that 
in  the  concentration  of  gas  encountered  on  an  average  in 
the  field,  the  life  of  the  comparatively  small  American  boxes 
was  sufficient  to  last  from  fifty  to  one  hundred  hours,  which 
is  longer  than  any  gas  attack  or  at  least  gives  time  to  get 
out  of  the  gassed  area. 

The  British  early  appreciated  the  necessity  of  knowing 
when  boxes  should  be  replaced.  They  accordingly  devised 
the  scheme  of  furnishing  with  each  mask  a  very  small  booklet 
tied  to  the  carrying  case  in  which  the  soldier  could  not  only 
enter  a  complete  statement  of  the  time  he  had  worn  the  mask 
but  also  the  statement  as  to  whether  it  was  in  gas  or  for 
drill  purposes  only.  The  soldier  was  then  taught  that  if  he 
had  worn  the  mask,  say  for  forty  hours,  he  should  get  a  new 
box.  But  the  scheme  didn't  work.  In  fact,  it  was  one  of 
those  things  which  foresight  might  have  shown  wouldn't  work. 
Indeed,  any  man  who  in  the  hell  of  battle  can  keep  such  a 
record  completely,  should  be  at  once  awarded  a  Distinguished 
Service  Medal. 

As  gas  warfare  developed  not  only  were  all  kinds  of  gas 
shells  sent  over  in  a  bunch  but  they  were  accompanied  by 
high  explosive,  shrapnel  and  anything  else  in  the  way  of 
trouble  that  the  enemy  possessed.  A  man  near  the  front  line, 
under  those  conditions,  had  all  he  could  do  and  frequently 
more  than  he  could  do,  to  get  his  mask  on  and  keep  it  on 
while  doing  his  bit.  Consequently  he  had  no  time,  even  if 
he  had  the  inclination,  to  record  how  long  he  had  the  mask 
in  the  various  gases. 

In  this  connection,  after  the  Armistice  was  signed  we  in 
the  field  were  requested  to  obtain  for  experimental  purposes 
10,000  canisters  that  had  been  used  in  battle.  Each  was  to 
be  labeled  with  the  length  of  time  it  had  been  worn  in  or 
out  of  gas,  and  if  in  gas,  the  name  of  each  gas  and  the  time 
the  mask  was  worn  in  it.  This  request  is  just  a  sample  of 
what  is  asked  by  those  who  do  not  realize  field  conditions. 
One  trip  to  the  front  would  have  convinced  the  one  making 
the  request  of  the  utter  impossibility  of  complying  with  it, 
for  really  no  man  knows  how  long  he  wears  a  mask  in  gas. 
With  gas  as  common  and  as  difficult  to  detect  (when  inter- 


DEFENSE  AGAINST  GAS  425 

mingled  with  high  explosive  gases  and  other  smells  of  the 
battle  field)  as  it  was  at  the  end  of  the  war,  each  man  wore 
the  mask  just  as  long  as  he  could,  simply  as  a  matter  of 
precaution. 

Before  hostilities  ceased  we  were  trying  out  a  method 
of  calling  in  say  fifty  canisters  per  division  once  a  week  for 
test  in  the  laboratory.  If  the  tests  showed  the  life  of  the 
canisters  to  be  short  new  canisters  would  be  issued.  While 
we  did  not  have  opportunity  to  try  out  this  plan,  it  gave 
promise  of  being  the  best  that  could  be  done.  With  gas 
becoming  an  every  day  affair,  the  only  other  alternative  would 
seem  to  be  to  make  issues  of  new  boxes  at  stated  intervals. 
On  the  other  hand  there  are  no  definite  records  of  casualties 
occurring  from  the  exhaustion  of  the  chemicals  in  the  box. 
Undoubtedly  some  did  occur,  but  they  were  very,  very  few. 
In  nearly  all  cases  the  masks  got  injured,  or  the  box  became 
rusted  through  before  the  chemicals  gave  out. 

Tonnage  and  Number  of  Masks  Required 

It  will  probably  be  a  shock  to  most  people  to  learn  that 
with  more  than  two  million  men  in  France  we  required  nearly 
1500  tons  of  gas  material  per  month.  This  tonnage  was  increas- 
ing, rather  than  decreasing,  to  cover  protective  suits,  gloves, 
pastes,  and  chloride  of  lime,  as  well  as  masks.  The  British  type 
respirator  was  estimated  to  last  from  four  to  six  months.  The 
active  part  of  the  war,  in  which  the  Americans  took  part, 
was  too  short  to  determine  whether  this  was  correct  or  not. 
The  indications  were,  however,  that  it  was  about  right,  con- 
sidering rest  periods  and  fighting  periods. 

With  the  new  American  mask,  with  its  much  stronger  and 
stiffer  face  material,  the  chances  are  that  the  life  will  be  con- 
siderably increased  although  the  more  constant  use  of  the 
mask  will  probably  offset  its  greater  durability.  A  longer 
life  of  mask  would  of  course  be  a  decided  advantage  as  it 
would  not  only  reduce  tonnage,  but  would  reduce  manufac- 
turing and  distribution  as  well.  The  estimates  on  which  we 
were  working  at  the  end  looked  forward  to  requiring  from 
the  United  States  about  one-third  pound  per  man  per  day  for 


426  CHEMICAL  WARFARE 

all  troops  in  France,  in  order  to  keep  them  supplied  with  gas 
defense  material  and  with  the  gases  used  offensively  by  gas 
troops.  All  gas  shell,  hand  grenades,  etc.,  used  by  other  than 
gas  troops  required  tonnage  in  addition  to  the  above. 

Summing  Up 

In  summing  up  then,  it  is  noted  that  there  are  several 
important  things  in  defense  against  gas.  First,  the  mask  which 
protects  the  eyes  and  the-  lungs.  Second,  the  training  that 
teaches  the  man  how  to  utilize  to  best  advantage  the  means 
of  protection  at  his  disposal,  whether  he  be  alone  or  among 
others.  Third,  protective  clothing  that  protects  hands  and 
feet  and  the  skin  in  general.  Fourth,  a  knowledge  of  gases 
and  their  tactical  use  that  will  enable  commanders,  whenever 
possible,  to  move  men  out  of  gas-infected  areas.  Fifth,  train- 
ing in  the  off eiiiiive  use  of  gas,  as  well  as  in  defensive  methods, 
to  teach  the  man  that  gas  has  no  uncanny  power  and  that  it  is 
simply  one  element  of  war  that  must  be  reckoned  with,  thus 
preventing  stampedes  when  there  is  really  no  danger. 

While  these  are  the  salient  points  in  defense  against  gas, 
above  them  and  beyond  them  lies  the  vigorous  offensive  use 
of  gas.  This  involves  not  only  the  research,  development  and 
manufacture  of  necessary  gases  in  peace  time,  but  also  the 
necessary  training  to  enable  our  nation  to  hurl  upon  the  enemy 
on  the  field  of  battle  chemical  warfare  materials  in  quantities 
he  cannot  hope  to  attain. 


CHAPTER  XXV 
PEACE  TIME  USES  OF  GAS 

''Peace  hath  her  victories  no  less  renowned  than  war/' 
Thus  runs  the  old  proverb.  In  ancient  times  war  profited  by 
peace  far  more  than  peace  profited  by  war  if  indeed  the  latter 
ever  actually  occurred.  The  implements  developed  for  the 
chase  in  peace  became  the  weapons  of  war.  This  was  true  of 
David's  sling  shot,  of  the  spear  and  of  the  bow.  Even  powder 
itself  was  probably  intended  and  used  for  scores  of  years  for 
celebrations  and  other  peaceful  events. 

The  World  War  reversed  this  story,  especially  in  its  later 
phases.  The  greater  part  of  the  war  was  fought  with  imple- 
ments and  machines  prepared  in  peace  either  for  war  or  for 
peaceful  purposes.  Such  implements  were  the  aeroplane,  sub- 
marine, truck,  automobile  and  gasoline  motors  in  general.  The 
first  gas  attack,  which  was  simply  an  adaptation  of  the  peace- 
time use  of  the  chemical  chlorine,  inaugurated  the  change.  Gas 
was  so  new  and  instantlj^  recognized  as  so  powerful  that  the 
best  brains  in  research  among  all  the  first-class  powers  were 
put  to  work  to  develop  other  gases  and  other  means  of  project- 
ing them  upon  the  enemy.  The  result  was  that  in  the  short 
space  of  three  and  one-half  years  a  number  of  substances-  were 
discovered,  or  experimented  with  anew,  that  are  aiding  to-day 
and  will  continue  to  aid  in  the  future  in  the  peaceful  life  of 
every  nation. 

Chlorine  is  even  more  valuable  than  ever  as  a  disinfectant 
and  water  purifier.  It  is  the  greatest  bleaching  material  in  the 
world,  and  has  innumerable  other  uses  in  the  laboratory.  Chlo- 
ropicrin,  cyanogen  chloride  and  cyanogen  bromide  are  found  to 
be  very  well  adapted  to  the  killing  of  weevil  and  other  similar 
insect  destroyers  of  grain.  Hydrocyanic  acid  gas  is  the  great- 
est destroyer  to-day  of  insect  pests  that  otherwise  would  ruin 

427 


428 


CHEMICAL  WARFARE 


the  beautiful  orange  and  lemon  groves  of  California  and  the 
South. 

Phosgene,  so  extensively  used  in  the  war  both  in  cloud  gas 


SALT      PRODUCTS 

IN  WAR  AND  PEACE  TIME  INDUSTRIES 


f 


■►      '-* 


saPt 


CHLORINE 

:WAR    GAS 
WATER   PUPIFICATI'^N 


i 


CAUSTl^-   SODA 


1 


CHLORIDE  OF  LIME 

iBLEACttlNG    PCWDER; 
.DISINFECTANT 


X-"' 
^J^ 


CHf.OROFORM 


1 


M  EXILIC 
SODIUM 


SOAPS 


CHLORACETIC 
ACID 


PH050ENE     SODIUM 
CYANIDE 

■,..SiN(-CCTANT 


i 

iNDIGO 


J 


SODIUM 

5ULPHOCARBOLATE 

MECiCIN  AL 


SODIUM 
SALICYLATE 

MECiClNAL. 


YLL.LOW    WOOL  GREEN  CRYSTACViOlE- 

■*"'  DYE  iDYE,  •«»»««<«*  DYE. 

CHLORA-  CYANOGEN   CHLORIDE 

CETOPHENONE  •  --/ap  Oas 

WAR    OAS 


Fig.  120. 


and  in  shell,  is  finding  an  ever  increasing  use  in  the  making  of 
brilliant  dyes — pinks,  greens,  blues  and  violets.  On  account  of 
its  cheapness  and  simplicity  of  manufacture,  it  has  great  pos- 
sibilities in  the   destruction  of  rodents  such  as  rats  around 


PEACE  TIME  USES  OF  GAS  429 

wharves,  warehouses  and  similar  places  that  are  inaccessible 
to  any  other  means  of  reaching  those  pests.  Since  phosgene 
is  highly  corrosive  of  steel,  iron,  copper  and  brass,  it  cannot 
be  used  successfully  in  places  where  those  metals  are  present. 

Instead  of  phosgene  for  killing  rodents  and  the  like  in  store- 
houses and  warehouses,  cyanogen  bromide  has  been  developed. 
This  is  a  solid  and  can  be  burned  like  an  ordinary  sulphur 
candle.  It  is  much  safer  for  the  purpose  of  fumigating  rooms 
and  buildings  than  is  hydrocyanic  acid  gas  when  so  used.  This 
is  for  the  reason  that  cyanogen  bromide  is  an  excellent  lachry- 
mator  in  quantities  too  minute  to  cause  any  injury  to  the 
lungs.  It  will  thus  give  warning  to  anyone  attempting  to  enter 
a  place  where  some  of  the  gas  may  still  linger. 

Among  tear  gases,  the  new  chloracetophenone,  a  solid,  is 
perhaps  the  greatest  of  all.  When  driven  off  by  heat  it  first 
appears  as  a  light  bluish  colored  cloud.  This  cloud  is  instantly 
so  irritating  to  the  eyes  that  within  a  second  anyone  in  the 
path  of  the  cloud  is  temporarily  blinded.  It  causes  considerable 
smarting  and  very  profuse  tears  which  even  in  the  smallest 
amount  continue  for  two  to  five  minutes.  In  greater  quan- 
tities it  would  continue  longer.  So  far  as  can  be  ascertained, 
it  is  absolutely  harmless  so  far  as  any  permanent  injuries  are 
concerned. 

Considering  that  it  is  instantly  effective,  that  minute  quan- 
tities are  unbearable  to  the  eyes,  that  it  can  be  put  in  hand 
grenades  or  other  small  containers  and  driven  off  by  a  heat- 
ing mixture  which  will  not  ignite  even  a  pile  of  papers,  and 
that  it  needs  no  explosion  to  burst  the  grenade  (all  that  is  used 
is  a  light  cap,  set  off  by  the  action  of  the  spring,  sufficient  to 
ignite  the  burning  charge),  the  future  will  see  every  police 
department  in  the  land  outfitted  with  chloracetophenone  or 
other  similar  grenades.  Every  sheriff's  office,  every  jail  and 
every  penitentiary  will  have  a  supply  of  them.  No  jail  break- 
ing, no  lynching,  no  rioting  can  succeed  where  these  grenades 
are  available.  Huge  crowds  can  be  set  to  weeping  instantly 
so  that  no  man  can  see  and  no  mob  will  continue  once  it  is 
blinded  with  irritating  tears.  More  than  that,  it  is  an  ex- 
tremely difficult  gas  to  keep  out  of  masks,  ordinary  masks  of 
the  "World  War  being  entirely  useless  against  it. 


430  CHEMICAL   WARFARE 

The  same  is  true  of  diphenylaminechlorarsine.  This  is  not 
a  tear  gas  but  it  is  extraordinarily  irritating  to  the  lungs,  throat 
and  nose,  where  it  causes  pains  and  burning  sensations,  and  in 
higher  concentrations  vomiting.  It  is  hardly  poisonous  at  all 
so  that  it  is  extremely  difficult  to  get  enough  to  cause  danger 
to  life.  This  is  mentioned  because  of  its  possible  use  for  the 
protection  of  bank  vaults,  safes,  and  strong  rooms  generally. 

There  are  many  other  gases  that  can  be  used  for  this  same 
purpose.  It  is  presumed  that  gases  that  are  not  powerful 
enough  to  kill  are  the  ones  desired,  and  there  are  half  a  dozen 
at  least  that  can  be  so  used.  If  desired  deadly  gases  can  just 
as  readily  be  used.  Already  a  number  of  inventors  are  at  work 
on  the  problem,  with  some  plans  practically  completely  worked 
out  and  models  made. 

It  has  been  suggested  that  one  of  these  gases  could  be 
used  by  trappers  in  trapping  wild  animals.  Hydrocyanic  acid 
gas  may  be  so  used.  It  acts  quickly  and  is  very  rapidly  dis- 
sipated. An  animal  exposed  to  the  fumes  would  die  quickly 
and  the  trap  be  safe  to  approach  within  two  minutes  after  it 
was  sprung.  It  is  said  that  the  loss  from  animals  working 
their  way  out  of  traps  by  one  means  or  another  is  nearly  20 
per  cent.  More  than  this,  it  would  meet  the  objections  of  the 
S.  P.  C.  A.  in  that  the  animal  would  not  suffer  from  having 
its  limbs  torn  and  lacerated  by  the  trap. 

Attempts  are  being  made  to  attack  the  locust  of  the  Philip- 
pines and  the  far  west  and  the  boll  weevil  of  the  cotton  states 
of  the  South.  So  far  these  tests  have  not  proven  more  success- 
ful than  other  methods,  but  inasmuch  as  the  number  of  gases 
available  for  trial  are  so  great  and  the  value  of  success  of  so 
m.uch  importance,  this  research  should  be  continued  on  a  large 
scale  to  definitely  determine  whether  poisonous  gas  can  be 
used  to  eradicate  these  pests — especially  the  boll  weevil. 

As  an  interesting  application  of  war  materials  to  peaceful 
uses,  we  may  consider  the  case  of  cellulose-acetate,  known  dur- 
ing the  war  as  ''aeroplane  dope,"  the  material  used  to  coat  the 
linen  covering  aeroplane  wings.  With  a  little  further  manipu- 
lation, this  cellulose-acetate,  or  aeroplane  dope,  becomes  arti- 
ficial silk — a  silk  that  to-day  is  generally  equal  to  the  best 
natural  silk — and  which  promises  in  the  future  to  become  a 


PEACE  TIME  USES  OF  GAS 


431 


standard  product  better  in  every  way  than  that  from  the  silk 
worm. 

These  few   examples   of  the  peacetime  value   of  gas   are 


COAL     PRODUCTS 

IN  WAR  AND  PEACE  TIME  INDUSTRIES 


I 

FUEL, 


^ 


CARBOLIC       Picmc 
ACID        ,       ACID 

'mcoicinal  0-  high  explo 
disinfcctantsive:  &■  dye: 

4^ 


BENZENE 


PONCEAU      CHLORPICRIN 

DYE:  WAR    GASi 


BROMBENZYLCYANIDE 

'WAR    GAS 


NITROBENZENE 

4^ 


h  r 


IPH^L 


DIPHeriTL- 
CHLORARSINE 

fWAR    GAS;  .,^ 

BUTTER  YELLOW 


■er%:l 


ANILINE 


ACET'^fitlDE 


Fig.  121, 


worthy  of  thought  from  another  standpoint.  Being  so  valu- 
able, their  use  in  peace  will  not  be  stopped.  If  they  are  thus 
manufactured  and  used  in  peace,  they  will  always  be  available 


432  CHEMICAL  WARFARE 

for  use  in  war,  and  as  the  experience  of  the  World  War  proved, 
they  certainly  will  be  so  used  even  should  anybody  be  foolish 
enough  to  try  to  abolish  their  use.  As  for  this  latter  idea,  the 
world  might  as  well  recognize  at  once  that  half-way  measures 
in  war  simply  invite  disaster. 

This  chapter  would  not  be  complete  without  a  brief  state- 
ment of  the  necessity  of  a  thoroughly  developed  chemical  in- 
dustry in  the  United  States  as  a  vital  national  necessity  if  the' 
United  States  is  to  have  real  preparedness  for  a  future  struggle. 
As  will  be  indicated  a  little  later,  no  one  branch  of  the  chemical 
industry  can  be  allowed  to  go  out  of  existence  without  endan- 
gering some  part  of  the  scheme  of  preparedness. 

Let  us  consider  first  the  coal  tar  industry.  Coal  tar  is  a 
by-product  of  coke  ovens  or  the  manufacture  of  artificial  gas 
from  coal.  The  coal  tar  industry  is  of  the  utmost  importance 
because  in  the  coal  tars  are  the  bases  of  nearly  all  of  the 
modern  dyes,  a  large  percentage  of  the  modern  medicines,  most 
of  the  modern  high  explosives,  a  large  proportion  of  poisonous 
gases,  modern  perfumes,  and  photographic  materials. 

A  consideration  of  these  titles  alone  shows  how  vital  the 
coal  tar  industry  is.  The  coal  tar  as  it  comes  to  us  as  a  by- 
product is  distilled,  giving  off  at  different  temperatures  a  series 
of  compounds  called  crudes.  Ten  of  these  are  of  very  great 
importance.  The  first  five  are  benzene,  toluene,  naphthalene, 
anthracene  and  phenol  (carbolic  acid).  The  second  group  com- 
prises xylene,  methylanthracene,  cresol,  carbazol  and  phenan- 
threne. 

These,  when  treated  with  other  chemicals,  produce  a  series 
of  compounds  called  intermediates,  of  which  there  are  some  300 
now  known.  From"  these  intermediates  by  different  steps  are 
produced  either  dyes,  high  explosives,  poisonous  gases,  pharma- 
ceuticals, perfumes  or  photographic  materials. 

We  have  all  heard  that  Germany  controlled  the  dye  in- 
dustry of  the  world  prior  to  the  World  War.  A  little  study 
of  the  above  brief  statement  of  what  is  contained  in  the  coal 
tar  industry  along  with  dyes  will  show  in  a  measure  one  of  the 
reasons  why  Germany  felt  that  she  could  win  a  war  against  the 
world.  That  she  came  so  desperately  close  to  winning  that  war 
is  proof  of  the  soundness  of  her  view. 


PEACE  TIME  USES  OF  GAS  433 

In  many  of  the  processes  are  needed  the  heavy  chemicals 
such  as  chlorine,  sulfuric  acid,  nitric  acid,  hydrochloric  acid 
and  the  like.  The  alcohol  industry  is  also  of  very  great  im- 
portance. Grain  alcohol  is  used  extensively  in  nearly  all 
research  problems  and  in  very  great  quantities  in  many  com- 
mercial processes  such  as  the  manufacture  of  artificial  silk  and 
foi"  gasolene  engines  in  addition  to  its  use  in  compounding  medi- 
cines. It  is  of  very  great  importance  to  the  Chemical  War- 
fare Service  in  that  from  grain  alcohol  is  obtained  ethylene 
gas,  one  of  the  three  essentials  in  the  manufacture  of  mustard 
gas.  While  this  ethylene  may  be  obtained  from  many  sources, 
the  most  available  source,  considering  ease  of  transportation 
and  keeping  qualities,  is  in  the  form  of  grain  alcohol. 

Allied  to  the  chemical  industries  just  mentioned  is  the 
nitrate  industry  for  making  nitric  acid  from  the  nitrogen  of 
the  air.  Nitrates  are  used  in  many  processes  of  chemical  man- 
ufacture and  particularly  in  those  for  the  production  of  smoke- 
less powders.  The  fertilizer  industry  is  of  large  importance 
because  it  deals  with  phosphorus,  white  phosphorus  being  not 
only  one  of  the  best  smoke  producing  materials  but  a  material 
that  is,  as  stated  elsewhere,  of  great  use  against  men  through 
its  powerful  burning  qualities. 

Another  point  not  mentioned  above  in  connection  with 
these  industries  is  the  training  of  chemists,  chemical  engineers 
and  the  building  up  of  plants  for  the  manufacture  of  chemicals, 
all  of  which  are  necessary  sources  of  supply  for  wartime  needs. 
Chemists  are  needed  in  the  field,  in  the  laboratory  and  in  man- 
ufacturing plants.  The  greater  their  number,  the  more  effi- 
ciently can  these  materials  be  handled,  and  since  chemicals 
as  such  will  probably  cause  more  than  50  per  cent  of  all  cas- 
ualties in  future  wars,  their  value  is  almost  unlimited. 

Instead  of  trying  to  ameliorate  the  ravages  of  war,  let  us 
turn  every  endeavor  towards  abolishing  all  war,  remembering 
that  the  most  scientific  nations  should  be  the  most  highly  civi- 
lized, and  the  ones  most  desirous  of  abolishing  war.  If  those 
nations  will  push  every  scientific  development  to  the  point 
where  by  the  aid  of  their  scientific  achievements  they  can  over- 
come any  lesser  scientific  peoples,  the  end  of  war  should  be  in 
sight. 


434  CHEMICAL  WARFARE 

However,  we  can  never  be  certain  that  war  is  abolished 
until  we  convince  at  least  a  majority  of  the  world  that  war 
is  disastrous  to  the  conqueror  as  well  as  to  the  conquered, 
and  that  any  dispute  can  be  settled  peacefully  if  both  parties 
will  meet  on  the  common  ground  of  justice  and  a  square  deal. 


CHAPTER  XXVI 
THE  FUTURE  OF  CHEMICAL  WARFARE 

The  pioneer,  no  matter  what  the  line  of  endeavor,  en- 
Xiounters  difficulties  caused  by  his  fellow-men  just  in  proportion 
as  the  thing  pioneered  promises  results.  If  the  promise  be 
small,  the  difficulties  usually  encountered  are  only  those  neces- 
sary to  make  the  venture  a  success.  If,  however,  the  results 
promise  to  be  great,  and  especially  if  the  rewards  to  the 
inventor  and  those  working  with  him  promise  to  be  consider- 
able, the  difficulties  thrown  in  the  way  of  the  venture  become 
greater  and  greater.  Indeed  whenever  great  results  are 
promised,  envy  is  engendered  in  those  in  other  lines  whose 
importance  may  be  diminished,  or  who  are  so  short-sighted 
as  to  be  always  opposed  to  progress. 

Chemical  warfare  has  had,  and  is  still  having,  its  full  share 
of  these  difficulties.  From  the  very  day  when  chlorine,  known 
to  the  world  as  a  benign  substance  highly  useful  in  sanitation, 
water  purification,  gold  mining  and  bleaching  was  put  into 
use  as  a  poisonous  gas,  chemical  warfare  has  loomed  larger 
and  larger  as  a  factor  to  be  considered  in  all  future  wars. 
Chlorine  was  first  used  in  the  cylinders  designed  for  shipping 
it.  These  cylinders  were  poorly  adapted  for  warfare,  and 
made  methods  of  preparing  gas  attacks  extremely  laborious, 
cumbersome  and  time-consuming. 

It  was  not  many  months,  however,  until  different  gases 
began  to  appear  in  large  quantities  in  shells  and  bombs,  while 
the  close  of  the  war,  3%  years  later,  saw  the  development 
of  gas  in  solid  form  whereby  it  could  be  carried  with  the 
utmost  safety  under  all  conditions — a  solid  which  could  become 
dangerous  only  when  the  heating  mixture,  that  freed  the  gas, 
was  properly  ignited. 

While  some  of  the  chemicals  developed  for  use  in  war  prior 

435 


436  CHEMICAL  WARFARE 

to  the  Armistice  have  been  made  known  to  the  world,  a  number 
or  others  have  not.  More  than  this,  every  nation  of  first  class 
importance  has  continued  to  pursue  more  or  less  energetically 
studies  into  chemical  warfare.  These  studies  will  continue, 
and  we  must  expect  that  new  gases,  new  methods  of  turning 
them  loose,  and  new  tactical  uses  will  be  developed. 

Already  it  is  clearly  foreseen  that  these  gases  will  be  used 
by  every  branch  of  the  Army  and  the  Navy.  While  chemicals 
were  not  used  by  the  Air  Service  in  the  last  war,  it  was  even 
then  realized  that  there  was  no  material  reason  why  they 
should  not  have  been  so  used".  That  they  will  be  used  in  the 
future  by  the  Air  Service,  and  probably  on  a  large  scale,  is 
certain.  The  Navy,  too,  will  use  gases,  and  probably  on  a 
considerable  scale.  Thus  chemical  materials  as  such  become 
the  most  universal  of  all  weapons  of  war. 

Some  of  the  poisonous  gases  are  so  powerful  in  minute 
quantities  and  evaporate  so  slowly  that  their  liberation  does 
not  produce  sufficient  condensation  to  cause  a  cloud.  Conse- 
quently, we  have  gases  that  cannot  be  seen.  Others  form 
clouds  by  themselves,  such,  for  instance,  as  the  toxic  smoke 
candle,  where  the  solid  is  driven  off  by  heating,  while  still 
others  cause  clouds  of  condensed  vapor.  This  brings  the  dis- 
cussion into  the  realm  of  ordinary  smokes  that  have  no 
irritating  and  no  poisonous  effects. 

These  smokes  are  extremely  valuable  where  the  purpose  is 
to  form  a  screen,  whether  it  be  to  hide  the  advance  of  troops 
or  to  cut  off  the  view  of  observers.  These  smokes  are  equally 
useful  on  land  and  on  sea.  So  great  is  the  decrease  in  efficiency 
of  the  rifle  or  machine  gun,  and  of  artillery  even  when  firing 
at  troops  that  cannot  be  seen,  that  smoke  for  screening  pur- 
poses will  be  used  on  every  future  field  of  battle.  When  firing 
•through  a  screen  of  smoke,  a  man  has  certainly  less  than 
one-quarter  the  chance  to  hit  his  target  that  he  would  have 
were  the  target  in  plain  view.  Since  smoke  clouds  may  or 
may  not  be  poisonous  and  since  smoke  will  be  used  in  every 
battle,  there  is  opened  up  an  unlimited  field  for  the  exercise 
of  ingenuity  in  making  these  smoke  clouds  poisonous  or  non- 
poisonous  at  will.  It  also  opens  up  an  unlimited  field  for  the 
well-trained  chemical  warfare  officer  who  can  tell  in  any  smoke 


THE  FUTURE  OF  CHEMICAL  WARFARE  437 

cloud  whether  gas  be  present  and  whether,  if  present,  it  is  in 
sufficient  concentration  to  be  dangerous. 

At  the  risk  of  repetition,  it  is  again  stated  that  there  is  no 
gas  that  will  kill  or  even  permanently  injure  in  any  quantity 
that  cannot  be  detected.  For  every  gas,  there  is  a  certain 
minimum  amount  in  each  cubic  foot  of  air  that  is  necessary 
to  cause  any  injury.  In  nearly  all  ga,ses^thisjninimum  amount  | 
is  sufficient  to  be  readily  noticeable  by  a  trained  chemical 
warfare  officer  through  the  sense  of  smell. 

It  would  be  idle  to  attempt  to  enumerate  the  ways  and 
means  by  which  chemicals  will  be  used  in  the  future.  In  fact, 
one  can  hardly  conceive  of  a  situation  where  gas  or  smoke  will  / 
not  be  employed,  for  these  materials  may  be  liquids  or  solids 
that  either  automatically,  upon  exposure  to  the  air,  turn  into 
gas,  or  which  are  pulverized  by  high  explosive,  or  driven  off 
by  heat.  This  varied  character  of  the  materials  enables  them 
to  be  used  in  every  sort  of  artillery  shell,  bomb  or  other  con- 
tainer carried  to  the  field  of  battle. 

SoUie  of  the  gases  ^re  extremely  powerful  as  irritants  to 
the  nose  and  throat  in  very  minute  quantities,  while  at  the 
same  time  being  highly  poisonous  in  high  concentrations. 
Diphenylchloroarsine,  used  extensively  by  the  Germans  in  high 
explosive  shell,  is  more  poisonous  than  phosgene,  the  most 
deadly  gas  in  general  use  in  the  past  war.  In  addition,  it 
has  the  quality  of  causing  an  intolerable  burning  sensation 
in  the  nose,  throat,  and  lungs,  in  extremely  minute  quantities. 
This  material  can  be  kept  out  of  masks  only  by  filters,  whereas 
true  gases  are  taken  out  by  charcoal  and  chemical  granules. 

There  is  still  another  quality  which  helps  make  chemical 
warfare  the  most  powerful  weapon  of  war.  Gas  is  the  orfly 
substance  used  in  war  which  can  be  counted  on  to  do  its  work  y 
as  efficiently  at  night  as  in  the  daytime.  Indeed,  it  is  often 
more^ effective  a-t  night  than  in^Uie^^time,  because  the  man 
who  goes  to  sleep  without  his  mask  on,  who  is  careless,  who 
loses  his  mask,  or  who  becomes  excited  in  the  darkness  of 
night,  becomes  a  casualty,  and  the  past  war  showed  that  these 
casualties  were  decidedly  numerous  even  when  the  troops  knew 
almost  to  the  minute  the  time  the  gas  would  arrive. 

Accordingly,   chemical   warfare   is   an   agency   that   must 


438.  CHEMICAL  WARFARE 

not  only  be  reckoned  with  by  every  civilized  nation  in  the 
future,  but  is  one  which  civilized  nations  should  not  hesitate 
to  use.  When  properly  safe-guarded  with  masks  and  other 
safety  devices,  it  gives  to  the  most  scientific  and  most  ingenious 
people  a  great  advantage  over  the  less  scientific  and  less 
ingenious.  Then  why  should  the  United  States  or  any  other 
highly  civilized  country  consider  giving  up  chemical  warfare? 
To  say  that  its  use  against  savages  is  not  a  fair  method  of 
I  fighting,  because  the  savages  are  not  equipped  with  it,  is 
I  arrant  nonsense.  No  nation  considers  such  things  today.  If 
they  had,  our  American  troops,  when  fighting  the  Moros  in 
the  Philippine  Islands,  would  have  had  to  wear  the  breechclout 
and  use  only  swords  and  spears. 

Notwithstanding  the  opposition  of  certain  people  who, 
through  ignorance  or  for  other  reasons,  have  fought  it, 
chemical  warfare  has  come  to  stay,  and  just  in  proportion 
as  the  United  States  gives  chemical  warfare  its  proper  place 
in  its  military  establishment,  just  in  that  proportion  will  the 
United  States  be  ready  to  meet  any  or  all  comers  in  the  future, 
for  the  United  States  has  incomparable  resources  in  the  shape 
of  the  crude  materials — power,  salt,  sulfur  and  the  like — that 
are  necessary  in  the  manufacture  of  gases. 

If,  then,  there  be  developed  industries  for  manufacturing 
these  gases  in  time  of  war,  and  if  the  training  of  the  army 
in  chemical  warfare  be  thorough  and  extensive,  the  United 
States  will  have  more  than  an  equal  chance  with  any  other 
nation  or  combination  of  nations  in  any  future  war. 

It  is  just  as  sportsman-like  to  fight  with  chemical  warfare 
materials  as  it  is  to  fight  with  machine  guns.  The  enemy  will 
know  more  or  less  accurately  our  chemical  warfare  materials 
and  our  methods,  and  we  will  have  the  same  information 
about  the  enemy.  It  is  thus  a  matching  of  wits  just  as  much 
as  in  the  days  when  the  Knights  of  the  Round  Table  fought 
with  swords  or  with  spears  on  horseback.  The  American  is 
a  pure  sportsman  and  asks  odds  of  no  man.  He  does  ask, 
though,  that  he  be  given  a  square  deal.  He  is  unwilling  to 
agree  not  to  use  a  powerful  weapon  of  war  when  he  knows 
that  an  outlaw  nation  would  use  it  against  him  if  that  outlaw 
nation  could  achieve  success  by  so  doing.    How  much  better 


THE  FUTURE  OF  CHEMICAL  WARFARE  439 

it  is  to  say  to  the  world  that  we  are  going  to  use  chemical 
warfare  to  the  greatest  extent  possible  in  any  future  struggle. 
In  announcing  that  we  would  repeat  as  always  that  we  are 
making  these  preparations  only  for  defense,  and  who  is  there 
who  dares  question  our  right  to  do  so? 


INDEX 


Absorbents,  Requirements  of,  237 

Testing,  259 
Absorptive  activity,  237 
Absorptive  capacity,  238 
Aeroplane,  Smoke  screen,  309 
American  Tissot  mask,  224 
Ammonia  canister,  230 
Ammonium  chloride  smoke,  327 
Animals,   Susceptibility   to   mustard 

gas,  173 
Anthracite  coal,  Activation  of,  249 
A.  R.  S.  mask,  203 
Arsenic  derivatives,  180 
Arsenic  trichloride.  Manufacture,  180 
Arsenic  trifliuoride,  Manufacture,  180 
Arsine,  proposed  use  of,  180 
Artillery,  Gas,  use  of,  by,  396 
Aviation,  Gas,  use  of,  by,  380,  399 

Baby  Incendiary  bomb,  340 

Barrages,  Gas,  use  of,  in,  376 

Benzyl  bromide,  16,  141 

Benzyl  chloride,  16 

Berger  mixture,  290 

Black  signal  smokes,  331 

Black  veiling  respirator,  195 

Blue  cross.   See  Diphenylchloroarsine 

Blue  pencil,  German,  346 

Bombs,  incendiary,  337 

Box  respirator,  American,  209 

English,  198 
Break  point  of  canisters,  262 
Bromoacetone,  16,  138 

German  manufacture,  140 
Bromobenzyl  cyanide,  16,  142 
Bromomethylethyl   ketone,    German 

manufacture,  140 
Bullets,  incendiary,  344 


Camouflage  gases,  23,  416 
Canister,  life  of.  Gas  concentration 
and,  132 

Temperature,  effect  of,  132 

Testing,  260 
Carbon  dioxide,  Manufacture,  129 
Carbonite,  250 
Carbon  monoxide,  190 

Canister,  191 

Manufacture,  128 
Cavalry,  Gas,  use  of,  by,  378 
Cement,  Soda  lime,  function  in,  257 
Charcoal,  239 

Active,  242 

German,  251 

Inactive,  242 

Manufacture,  242 

Raw  material,  239 

Substitutes,  249 

Tests  of,  253 

Theory  of  action,  241 
Chemical    Service    Section,    Organi- 
zation, 34 
Chemical  Warfare,  Future  of,  435 

Gases  used  in,  24 

Historical,  1 

Officers,  duties  of,  369 

Strategy,  relation  to,  363 
Chemical  Warfare  Service,  Adminis- 
trative division,  36 

A.  E.  F.,  organization,  72 

Development  division,  61 

Edgewood  arsenal,  53 

Gas  defense  division,  48 

Liaison  officers,  70 

Medical  division,  68 

Organization,  35 

Proving  division,  63 


441 


442 


INDEX 


Chemical  Warfare  Service, 
Research  division,  38 
Training  division,  65 
Chemical  Warfare  troops,  92 
Chenard  bomb,  340 
Chlorine,  116 

Manufacture,  117 
Properties,  123 
Chloroacetone,  16 
Chloroacetophenone,  16 
Chloromethyl  chloroformate,  21 
Chloropicrin,  21 

Manufacture,  145 
Physiological  test,  146 
Properties,  146 
Protection,  147 
Tactical  use,  148 
Chlorovinyldichloroarsine,  188 
ChlorosuKonic  acid.  Smoke  material, 

use  as,  286 
Cloud  gas,  10,  116,  390 
Coalite,  250 

Cocoanut  shell  charcoal,  239 
Cohune  nut  charcoal,  240 
Complexene,  201 

Horse  masks,  use  in,  278 
Cottrell  Precipitation  Tube,  299 

Darts,  incendiary,  343 
Density  of  smoke  clouds,  295 
Development  Division,  C.  W.  S.,  61 
Dichloroethyl  sulfide,  22,  80,  105 

Detection,  166 

Historical,  151 

Manufacture,  152,  161 

Mixtures,  melting  point  of,  164 

Properties,  163 

Tactical  use,  175,  417 

Toxicity,  168 

Vesicant  action,  171 
/3,  /3'-Dichlorodivinylchloroarsine,  189 
Dihydroxy ethyl  sulfide,  160 
Diphenylchloroarsine,  22, 182 

Manufacture,  183 
Diphenylcyanoarsine,  185 
Diphosgene.      See  Trichloromethyl 
chloroformate, 


Dog  mask,  280 
Doughnut  filter,  324 
Dressier  tunner  kiln,  248 
D-Shell,  134 
Dugout  blankets,  283 
Dyes  for  signal  smokes,  333 

Edgewood  arsenal,  C.  W.  S.,  53 
Efficiency  test.  Absorbents,  259 

Canisters,  262 
Ethyldichloroarsine,  185 
Ethylene,  Manufacture  of,  155,  158 
Ethylene  chlorhydrin,  158 
Ethyl  iodoacetate,  16,  141 
Explosive  dispersion,  314 

''Fkst  gas  attack,"  10 

First  gas  regiment,  93 

Flammenwerfer,  349 

Flaming  gun,  347,  401 

Food,  protection  of,  against  mustard 

gas,  422 
French  artillery  mask,  202 


Gas,  Defense  against,  405 

Effectiveness  of,  375,  385 

Humanity  of,  13,  370,  387 

Offensive  use  of,  385 

Permanency  of,  378 

Requirements  of,  116,  395 
Gas  alarms,  422 
Gas  cloud,  height  and  spread,  394 

Smoke  in,  311,  403 
Gas  cylinder.  Mobile,  17 
Gas  defense  division,  C.  W."S.,  48 
Gases,  Detection  of,  415 

Peace  uses  of,  427 

Pharmacology,  353 
Gas  and  Flame  Regiment,  34 
Gas  mask.  Development,  195 

Physiological  features,  232 

Testing,  259 

See  also  names  of  various  masks 
Gas  shell,  Markings,  28,  404 

Value,  18,  396 


INDEX 


443 


Gassing  chamber,  354 
Gas  training,  413 

In  France,  81 

Value  in  peace,  373,  383 
Gas  warfare.  Fundamentals,  388 

Humanity,  13,  370,  387 
German  mask,  205 
Greasene,  201 
Green  Cross  shell,  148 
Green-T  Stoff,  142 

Hand  grenade,  incendiary,  345 

Hanlon  field,  111 

Hardness,  Absorbents,  test  of,  259 

Hague  conference.  Poison  gases, 
action  on,  6 

Homomartonite,  16, 138 

HopcaUte,  Carbon  monoxide  absor- 
bent, 193 

Horse  boots,  280 

Horse  mask,  277 

Humanity,  Gas  warfare,  13,  370,  387 

Hypo  helmet,  196 

Incendiary  materials,  336 

Tactical  use  of,  402 
Infantry,  Gas,  use  of,  by,  377,  400 
Intelligence  section,  113 
Inter-allied  gas  conference,  79 
Irritants,  Efficiency  of,  389 

Testmg,  359 
Ivory  nut  charcoal,  241 

Kieselguhr,  Soda  lime,  function    in, 

257 
Kupramite,  230 

Lachrymators,  15,  137 

Comparative  value,  143 
Protection,  143 
Testing,  356 
Lachrymatory  shell.  Tactical  value, 

15 
Lamp  black,"  Charcoal  from,  250 
Lantern  test.  Mustard  gas,  166 
Leak  detecting  apparatus,  266 
Leakage,  Canister,  testing  of,  261 


Levinstein  reactor,  158 

Lewisite,  23,  187 

Liaison  officers,  70 

Lime,  Soda  lime,  function  in,  257 

Livens'  projector,  18,  391 

Livens '  smoke  drum,  304 

M-2  Mask,  201 
Man  test,  262 
Martonite,  16,  138 
Mask,  Development,  405 

Disinfection,  269 

Field  tests,  270 

Issuance,  423 

See  also  Gas  mask 

See  also  Names  of  masks 
Mechanical  dispersion,  313 
Medical  division,  C.  W.  S.,  68 
Medical  section,  A.  E.  F.,  114 
Methyldichloroarsine,  181 
Moisture,  Absorbents,  tests  of,  259 
Mustard  gas.    See  Dichloroethyl  sul- 
fide. 

Navy,  Canister,  230 

Gas,  use  of,  by,  381 

Smoke  funnel,  305 
Nelson  cell,  117 

"Nineteen   nmeteen"   canister,   325 
"Nineteen  nineteen"  Model  Ameri- 
can Mask,  225 


Odors,  Testing  of,  358 
Oleum,  Smoke  material. 
Overall  suit,  273 


as,  286 


PaUte.    See  Chloromethyl  chlorofor- 

mate 
Penetration  apparatus.  Toxic  smoke, 

measurement  of,  315 
P-Hehnet,  197 
PH-Heknet,  197 
Phosgene,  14,  126 

Manufacture,  127 

Properties,  130 

Protection,  131 

SheU  filling,  132 

Tactical  use,  134 


444 


INDEX 


Phosphorus,  Smoke  material,  286,  382 

Stokes'  mortar,  use  in,  393 

See  also  Smoke 
Physiological  action,  Phosgene,  135 

Mustard  gas,  168 

Toxic  Smokes,  316 
Pressure  drop  apparatus,  266 
Protective  clothing,  272 
Protective  gloves,  274 
Protective  ointments,  275 
Proving  division,  C.  W.  S.,  63 
Pumice   stone.    Phosgene   shell,    use 
in,  130,  135 

Research  division,  C.  W.  S.,  38 
Resistance,  Canister,  test  of,  261 

Decreased,    410 
Respirator,  See  Gas  mask,  Mask 

Sag  paste,  277 
Screening  smokes,  285 

See  also  Smoke 
Screening  power,  Smoke  cloud,  285 
Selenious       acid.        Mustard       gas 

detector,  166 
Shell,  Gas,  Filling  of,  132 

Value,  18,  396 

Incendiary,  344 

Markings,  28,  404 

Pumice  stone  and  phosgene  in, 
130,  135 

Smoke,  303 
Ships,  Screening  Smoke,  299,  305 
Shrapnel,  Gas  in  connection  with,  379 
Signal  smokes,  ,330 

Tactics,  333 
Silicon  tetrachloride,  Smoke  material, 

use  as,  290 
Smoke,    Intensity,  measurement   of, 
296 

Tactical  value,  310,  402 

Use  in  offense,  401 

See  also,  Screening,    Signal  and 
Toxic  Smokes 
Smoke  box,  299 
Smoke  candle,  301,  372 

Toxic,  318 


Smoke  cloud.   Properties,   116,    285, 

395 
Smoke  drum,  304 
Smoke  filters,  322 

Felt,  324 

Paper,  323 

Testing,  327 

Theory,  326 
Smoke  funnel,  305 
Smoke  grenade,  302 
Smoke  knapsack,  306 
Smoke  particles.  Measurement  of,  292 

Size  of,  291 
Smoke  screen.  Purpose  of,  309 
Smoke  shell,  303,  307 
Smoke  signals,  333 
Sneezing   gas.    See    Diphenylchloro- 

arsine 
Soda  lime.  Composition,  256 

Requirements,  255 
Sodium  hydroxide.  Soda  lime,  func- 
tion in,  257 
Sodium    permanganate.    Soda  lime, 

function  in,  257 
"SoHdoil",  336 
Spray  nozzles,  357 
Staff  troops,  C.  W.  S.,  92 
Standard  Box  respirator,  198 
Stokes'  mortar,  20,  392 
Sulfur  chloride.  Manufacture,  157 
Sulfuric  acid  smoke,  328 
Sulfur  trioxide.  Smoke  material,    use 

as,  289 
SuperpaUte.      See      Trichloromethyl 
chloroformate 

Tactical  use,  Chloropicrin,  148 

Dichloroethyl  sulfide,  175,  417 

Gases  in  offense,  385 

Incendiary  materials,  402 

Lachrymatory  shell,  15 

Phosgene,  134 

Screening  smokes,  310,  402 

Signal  smokes,  333  ' 
Tactics,  Chemical  Warfare  and,  363 
Tanks,  Smoke  screen  for,  309 
Thermal  dispersion,  313 


INDEX 


445 


Thermit,  Uses,  393 

Tin    tetrachloride,   Smoke    material, 

use  as,  289 
Tissot  mask,  202 
Titanium        tetrachloride,       Smoke 

material,  use  as,  290 
Tobacco  smoke,  328 
Total  obscuring  power  of  smoke,  295 
Touch  method.   Irritants,  testing  of, 

362 
Toxicity,  Gases,  testing  of,  for,  353 
Toxic  smoke,  313 

Candle,  B.  M.,  319 

Candle,  Dispersoid,  320 

Penetration,  314 

Quantitative  relationship,  316 
Training  division,  C.  W.  S.,  65 
Trench  mortar,  20,  392 
Trichloromethyl  chloroformate,  20 
Trichloronitromethane.      See    Chlo- 

ropicrin 
/3,  /3',  /3"-TrichIorotrivinyIarsine,  189 


T-StofT,  141 
Tyndall  meter,  299 

Ultramicroscope,     Smoke     particles, 
measurements  of,  292 

Vapor  tests.  Irritants,  testing  of,  359 

Versatility  of  absorbents,  238 

Vincennite,  15,  180 

Vision  chart,  271 

' '  Vomiting  gas. ' '    See  Chloropicrin 

War  gas.  See  Gases 
War,  humanity  of,  6 
Wave  attack.  Disadvantages,  16 

Xylyl  bromide,  16,  141 

Yellow  cross.    See  Dichloroethyl  sul- 
fide 
Yellow  smoke,  331 
Yperite.     See  Dichloroethyl  sulfide 


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